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• W2141766281 abstract "The interactions of a range of synthetic peptidoglycan derivatives with PGRP-Iα and PGRP-S have been studied in real-time using surface plasmon resonance. A dissociation constant of KD = 62 μm was obtained for the interaction of peptidoglycan recognition protein (PGRP)-Iα with the lysine-containing muramyl pentapeptide (compound 6). The normalized data for the lysine-containing muramyl tetra- (compound 5) and pentapeptide (compound 6) showed that these compounds have similar affinities, whereas a much lower affinity for muramyl tripeptide (compound 3) was measured. Similar affinities were obtained when the lysine moiety of the muramyl peptides was replaced by meso-diaminopimelic acid (DAP). Furthermore, the compounds that contained only a stem peptide (pentapeptide, compound 1) and (DAP-PP, compound 2) as well as muramyldipeptide (compound 3) exhibited no binding indicating that the muramyltripeptide (compound 4) is the smallest peptidoglycan fragment that can be recognized by PGRP-Iα. Surprisingly, PGRP-S derived significantly higher affinities for the DAP-containing fragments to similar lysine-containing derivatives, and the following dissociation constants were measured: muramylpentapeptide-DAP, KD = 104 nm; muramyltetrapeptide-DAP, 92.4 nm; and muramyltripeptide-DAP, 326 nm. The binding profiles were rationalized by using a recently reported x-ray crystal structure of PGRP-Iα with the lysine-containing muramyltripeptide (4Beutler B. Mol. Immunol. 2004; 40: 845-859Crossref PubMed Scopus (886) Google Scholar). The interactions of a range of synthetic peptidoglycan derivatives with PGRP-Iα and PGRP-S have been studied in real-time using surface plasmon resonance. A dissociation constant of KD = 62 μm was obtained for the interaction of peptidoglycan recognition protein (PGRP)-Iα with the lysine-containing muramyl pentapeptide (compound 6). The normalized data for the lysine-containing muramyl tetra- (compound 5) and pentapeptide (compound 6) showed that these compounds have similar affinities, whereas a much lower affinity for muramyl tripeptide (compound 3) was measured. Similar affinities were obtained when the lysine moiety of the muramyl peptides was replaced by meso-diaminopimelic acid (DAP). Furthermore, the compounds that contained only a stem peptide (pentapeptide, compound 1) and (DAP-PP, compound 2) as well as muramyldipeptide (compound 3) exhibited no binding indicating that the muramyltripeptide (compound 4) is the smallest peptidoglycan fragment that can be recognized by PGRP-Iα. Surprisingly, PGRP-S derived significantly higher affinities for the DAP-containing fragments to similar lysine-containing derivatives, and the following dissociation constants were measured: muramylpentapeptide-DAP, KD = 104 nm; muramyltetrapeptide-DAP, 92.4 nm; and muramyltripeptide-DAP, 326 nm. The binding profiles were rationalized by using a recently reported x-ray crystal structure of PGRP-Iα with the lysine-containing muramyltripeptide (4Beutler B. Mol. Immunol. 2004; 40: 845-859Crossref PubMed Scopus (886) Google Scholar). The innate immune system is an ancient evolutionary system of defense against microbial infections (1Hoffmann J.A. Nature. 2003; 426: 33-38Crossref PubMed Scopus (1145) Google Scholar, 2Janeway C.A. Medzhitov R. Annu. Rev. Immunol. 2002; 20: 197-216Crossref PubMed Scopus (6246) Google Scholar, 3Medzhitov R. Janeway C.A. Science. 2002; 296: 298-300Crossref PubMed Scopus (1690) Google Scholar, 4Beutler B. Mol. Immunol. 2004; 40: 845-859Crossref PubMed Scopus (886) Google Scholar). It responds rapidly to highly conserved families of structural patterns, called pathogen-associated molecular patterns (PAMPs), 4The abbreviations used are: PAMP, pathogen-associated molecular pattern; PGN, peptidoglycan; TLR, Toll-like receptor; PGRP, peptidoglycan recognition protein; DAP, meso-diaminopimelic acid; SPR, surface plasmon resonance; DMF, dimethylformamide; Fmoc, N-(9-fluorenyl)methoxycarbonyl; MALDI-TOF, matrix-assisted laser desorption ionization time-of-flight; MDP, muramyldipeptide; RU, resonance unit(s); Lys-PP, pentapeptide; MTP, muramyltripeptide; MTrP, muramyltetrapeptide; MPP, muramylpentapeptide; HRMS, high resolution mass spectrometry; PES, polyethersulfone. which are integral parts of pathogens, and are perceived as danger signals by the host. Examples of PAMPs include bacterial cell wall structures that are absent from the host such as lipopolysaccharide of Gram-negative bacteria, lipoteichoic acid, mannans, DNA sequences containing unmethylated CpG dinucleotides, flagellin, and peptidoglycan (PGN) (2Janeway C.A. Medzhitov R. Annu. Rev. Immunol. 2002; 20: 197-216Crossref PubMed Scopus (6246) Google Scholar, 3Medzhitov R. Janeway C.A. Science. 2002; 296: 298-300Crossref PubMed Scopus (1690) Google Scholar). The recognition of PAMPs is mediated by sets of highly conserved pattern recognition receptors (5Van Amersfoort E.S. Van Berkel T.J.C. Kuiper J. Clin. Microbiol. Rev. 2003; 16: 379-414Crossref PubMed Scopus (619) Google Scholar), each of which binds to a variety of PAMPs. Cellular activation by these receptors results in acute inflammatory responses that include the production of a diverse set of cytokines and chemokines, direct local attack against the invading pathogen, and the initiation of responses that activate and regulate the adaptive component of the immune response. The discovery of Toll-like receptors (TLRs) less than a decade ago has advanced our understanding of the early events in microbial recognition and response and the subsequent development of an adaptive immune response (6Beutler B. Hoebe K. Du X. Ulevitch R.J. J. Leukocyte Biol. 2003; 74: 479-485Crossref PubMed Scopus (502) Google Scholar, 7Lien E. Ingalls R.R. Crit. Care Med. 2002; 30 (-S11): S1Crossref PubMed Scopus (252) Google Scholar, 8O'Neill L.A.J. Science. 2004; 303: 1481-1483Crossref PubMed Scopus (71) Google Scholar, 9Check W. Asm News. 2004; 70: 317-322Google Scholar, 10O'Neill L.A.J. Trends Immunol. 2004; 25: 687-693Abstract Full Text Full Text PDF PubMed Scopus (131) Google Scholar, 11Schmitz F. Mages J. Heit A. Lang R. Wagner H. Eur. J. Immunol. 2004; 34: 2863-2873Crossref PubMed Scopus (86) Google Scholar, 12Pasare C. Medzhitov R. Curr. Opin. Immunol. 2003; 15: 677-682Crossref PubMed Scopus (116) Google Scholar). The Toll protein was first discovered in Drosophila, in which it has a pivotal role in embryonic development and microbial detection. Subsequently, a family of proteins structurally related to Toll was identified in higher organisms. Collectively, these transmembrane receptor proteins are referred to as TLRs. To date, eleven members of the mammalian TLR family have been identified, each potentially recognizing a discrete class of PAMP (13Tsan M.F. Gao B.C. J. Leukocyte Biol. 2004; 76: 514-519Crossref PubMed Scopus (603) Google Scholar). For example, lipopolysaccharides are recognized by TLR4, bacterial flagellin by TLR5, double-stranded RNA by TLR3 (14Sarkar S.N. Peters K.L. Elco C.P. Sakamoto S. Pal S. Sen G.C. Nat. Struct. Mol. Biol. 2004; 11: 1060-1067Crossref PubMed Scopus (310) Google Scholar), and bacterial DNA by TLR9. The most recently discovered member of this family, TLR11, plays a critical role in the recognition and control of uropathogenic bacteria, and two recent studies have demonstrated that TLR3 is involved in the recognition of single-stranded viral RNA. Although it was initially believed that TLR2 in combination with TLR1 or TLR6 recognizes PGN, recent studies with highly purified PGN indicate otherwise (15Travassos L.H. Girardin S.E. Philpott D.J. Blanot D. Nahori M.A. Werts C. Boneca I.G. EMBO Rep. 2004; 5: 1000-1006Crossref PubMed Scopus (396) Google Scholar). Instead, it appears that NOD proteins (NOD1 and NOD2) (16Inohara N. Nunez G. Nat. Rev. Immunol. 2003; 3: 371-382Crossref PubMed Scopus (869) Google Scholar, 17Chamaillard M. Girardin S.E. Viala J. Philpott D.J. Cell. Microbiol. 2003; 5: 581-592Crossref PubMed Scopus (276) Google Scholar), and peptidoglycan recognition proteins (PGRPs) (18Dziarski R. Mol. Immunol. 2004; 40: 877-886Crossref PubMed Scopus (301) Google Scholar) are the pattern-recognition receptors that detect PGN. PGRPs are a relatively new class of pattern-recognition receptors that are highly conserved from insects to mammals (19Liu C. Xu Z.J. Gupta D. Dziarski R. J. Biol. Chem. 2001; 276: 34686-34694Abstract Full Text Full Text PDF PubMed Scopus (295) Google Scholar, 20Kang D.W. Liu G. Lundstrom A. Gelius E. Steiner H. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 10078-10082Crossref PubMed Scopus (409) Google Scholar, 21Werner T. Liu G. Kang D. Ekengren S. Steiner H. Hultmark D. Proc. Natl. Acad. Sci. U. S. A. 2000; 97: 13772-13777Crossref PubMed Scopus (446) Google Scholar). Drosophila has 13 PGRP genes that are transcribed into at least 17 PGRPs (21Werner T. Liu G. Kang D. Ekengren S. Steiner H. Hultmark D. Proc. Natl. Acad. Sci. U. S. A. 2000; 97: 13772-13777Crossref PubMed Scopus (446) Google Scholar). These PGRPs can be divided in extracellular (e.g. PGRP-SA), transmembrane (e.g. PGRP-LC), and intracellular or secreted (e.g. PGRP-LE) proteins (18Dziarski R. Mol. Immunol. 2004; 40: 877-886Crossref PubMed Scopus (301) Google Scholar). To date, four PGRPs have been discovered in humans, namely PGRP-S, PGRP-Iα, PGRP-Iβ, and PGRP-L (19Liu C. Xu Z.J. Gupta D. Dziarski R. J. Biol. Chem. 2001; 276: 34686-34694Abstract Full Text Full Text PDF PubMed Scopus (295) Google Scholar, 20Kang D.W. Liu G. Lundstrom A. Gelius E. Steiner H. Proc. Natl. Acad. Sci. U. S. A. 1998; 95: 10078-10082Crossref PubMed Scopus (409) Google Scholar). The different PGRPs may exhibit a selectivity for PGN derived from a particular group of microbes. In this respect, PGNs are large polymers composed of alternating β(1Hoffmann J.A. Nature. 2003; 426: 33-38Crossref PubMed Scopus (1145) Google Scholar, 2Janeway C.A. Medzhitov R. Annu. Rev. Immunol. 2002; 20: 197-216Crossref PubMed Scopus (6246) Google Scholar, 3Medzhitov R. Janeway C.A. Science. 2002; 296: 298-300Crossref PubMed Scopus (1690) Google Scholar, 4Beutler B. Mol. Immunol. 2004; 40: 845-859Crossref PubMed Scopus (886) Google Scholar)-linked N-acetylglucosamine (GlcNAc) and N-acetylmuramic acid (MurNAc) residues, cross-linked by short peptide bridges (see Fig. 1) (22Schleifer K.H. Kandler O. Bacteriol. Rev. 1972; 36: 407-477Crossref PubMed Google Scholar). Depending on the amino acid composition of position 3 of the peptide chain, PGNs are classified as either l-lysine-type (Lys-type) or meso-diaminopimelic acid-type (DAP-type). The lysine-type, typical for Gram-positive bacteria, is normally connected to the d-Ala of another peptide chain by a short bridge varying in length and amino acid composition, depending on the bacteria. In the case of Gram-negative bacteria and Gram-positive bacilli, DAP-type is normally found as the third amino acid and is directly connected to d-Ala of another peptide chain. Drosophila PGRP-SA has been shown to interact with lysine-type PGN, activating the Toll receptor pathway (23Michel T. Reichhart J.M. Hoffmann J.A. Royet J. Nature. 2001; 414: 756-759Crossref PubMed Scopus (619) Google Scholar). On the other hand, PGRP-LC and PGRP-LE recognize DAP-type PGN activating the Imd/Relish pathway (24Werner T. Borge-Renberg K. Mellroth P. Steiner H. Hultmark D. J. Biol. Chem. 2003; 278: 26319-26322Abstract Full Text Full Text PDF PubMed Scopus (157) Google Scholar, 25Ramet M. Manfruelli P. Pearson A. Mathey-Prevot B. Ezekowitz R.A.B. Nature. 2002; 416: 644-648Crossref PubMed Scopus (594) Google Scholar, 26Choe K.M. Werner T. Stoven S. Hultmark D. Anderson K.V. Science. 2002; 296: 359-365Crossref PubMed Scopus (490) Google Scholar, 27Gottar M. Gobert V. Michel T. Belvin M. Duyk G. Hoffmann J.A. Ferrandon D. Royet J. Nature. 2002; 416: 640-644Crossref PubMed Scopus (534) Google Scholar, 28Leulier F. Parquet C. Pili-Floury S. Ryu J.H. Caroff M. Lee W.J. Mengin-Lecreulx D. Lemaitre B. Nat. Immunol. 2003; 4: 478-484Crossref PubMed Scopus (459) Google Scholar). PGRPs have high homology with the T7 lysozyme, a type 2 N-acetylmuramoyl-l-alanine amidase that hydrolyzes the bond between MurNAc and l-Ala of PGN (29Cheng X.D. Zhang X. Pflugrath J.W. Studier F.W. Proc. Natl. Acad. Sci. U. S. A. 1994; 91: 4034-4038Crossref PubMed Scopus (203) Google Scholar). In this respect, Drosophila PGRP-SC1b and PGRP-LB have been shown to possess amidase activity. (30Mellroth P. Karlsson J. Steiner H. J. Biol. Chem. 2003; 278: 7059-7064Abstract Full Text Full Text PDF PubMed Scopus (286) Google Scholar) Each of the four mammalian PGRPs (PGRP-L, PGRP-Iα, PGRP-Iβ, and PGRP-S) is able to bind peptidoglycan; however, possible selectivities for lysine or DAP-type PGN have either not been determined or remain controversial. In addition, the mode of cellular activation and bactericidal activity of these PGRPs is largely unknown. The limited data for PGRP-L indicates that this protein exhibits lytic activity (31Wang Z.M. Li X.N. Cocklin R.R. Wang M.H. Wang M. Fukase K. Inamura S. Kusumoto S. Gupta D. Dziarski R. J. Biol. Chem. 2003; 278: 49044-49052Abstract Full Text Full Text PDF PubMed Scopus (191) Google Scholar, 32Gelius E. Persson C. Karlsson J. Steiner H. Biochem. Biophys. Res. Commun. 2003; 306: 988-994Crossref PubMed Scopus (136) Google Scholar). The function of PGRP-Iα and PGRP-Iβ is unknown, and most research has thus far focused on PGRP-S. Mouse PGRP-S found in neutrophil tertiary granules participates in the intracellular neutralization of bacteria. Mice deficient in this PGRP are much more susceptible to intraperitoneal infections with low pathogenic Gram-positive bacteria. (33Dziarski R. Platt K.A. Gelius E. Steiner H. Gupta D. Blood. 2003; 102: 689-694Crossref PubMed Scopus (152) Google Scholar) However, bovine PGRP-S, located in neutrophil and eosinophil granules, has been shown to inhibit the growth of both Gram-positive and -negative bacteria (34Tydell C. Yount N. Tran D. Yuan J. Selsted M.E. J. Biol. Chem. 2002; 277: 19658-19664Abstract Full Text Full Text PDF PubMed Scopus (113) Google Scholar). To determine in the ligand requirements for various PGRPs, we have synthesized a range of partial structures of PGN (see Fig. 1) that contain lysine or DAP as the third amino acid. The interactions of these compounds with human PGRP-S and the C-terminal domain of human PGRP-Iα containing two tandem domains have been studied in real-time using surface plasmon resonance (SPR). Procedures for the expressing recombinant PGRP-IαC (residues 177-341) by in vitro folding from Escherichia coli inclusion bodies have been described previously (35Guan R.J. Malchiodi E.L. Wang Q. Schuck P. Mariuzza R.A. J. Biol. Chem. 2004; 279: 31873-31882Abstract Full Text Full Text PDF PubMed Scopus (49) Google Scholar). Compound 6: Sieber Amide resin (36Sieber P. Tetrahedron Lett. 1987; 28: 2107-2110Crossref Scopus (148) Google Scholar) (100 mg, 42 μmol, Novabiochem) was swelled in dry dimethylformamide (DMF, ∼120 min, 3 ml), treated with 20% piperidine in DMF (3 × 5 min, 3 × 2 ml), washed with freshly distilled DMF (3 × 3 ml), and then reacted with Fmoc-d-Ala-OH (26.12 mg, 84 μmol, Novabiochem) in DMF by using PyBOP (43.7 mg, Novabiochem), 1-hydroxybenzotriazole (11 mg, Aldrich), and N,N-diisopropylethylamine (29.2 μl, Alfa Aesar, Ward Hill, MA). Progress of the reaction was monitored by the Kaiser test. After completion of the coupling, the resin was washed with (3 × 3 ml), and the Fmoc protecting group was removed with 20% piperidine in DMF (3 × 5 min, 3 × 2 ml). The reaction cycle was repeated using Fmoc-d-Ala-OH (26.1 mg, 84 μmol), Fmoc-l-Lys(Mtt)-OH (52.4 mg, 84 μmol), Fmoc-d-isoglutamine (30.9 mg, 84 μmol), Fmoc-l-Ala-OH (26.12 mg, 84 μmol, Novabiochem), and, subsequently, 2-N-acetyl-1-β-O-allyl-4,6-benzylidene-3-muramic acid (37Chowdhury A.R. Siriwardena A. Boons G.J. Tetrahedron Lett. 2002; 43: 7805-7807Crossref Scopus (19) Google Scholar) (35.4 mg, 84 μmol). The resulting resin-bound glycopeptide was washed with DMF (3 × 3 ml), dichloromethane (7 × 3 ml), and methanol (3 × 3 ml). The resin was dried in vacuo for 4 h, reswelled in dichloromethane (DCM) (∼5 ml), and filtered. The glycopeptide was released by treatment of the resin with 2% trifluoroacetic acid in DCM (10 × 2 ml). The combined washings were concentrated under reduced pressure and co-evaporated with toluene (3 × 10 ml) to remove traces of trifluoroacetic acid. The crude product was subjected to 20% trifluoroacetic acid in DCM to ensure complete removal of the benzylidene protecting group. The resulting product was purified by Sephadex G15 size exclusion column (Amersham Biosciences) chromatography to give (allyl-2-N-acetyl-3-O-muramyl)-l-alanyl-d-isoglutamyl-l-lysine (23.4 mg, 70%) as a white amorphous solid. 1H NMR (500 MHz, D2O): δ = 5.87-5.93 (1H, m, OCH2CHCH2), 5.25-5.32 (2H, dd, OCH2CHCH2), 4.53 (1H, d, H1, J = 8.3 Hz), 4.13-4.35 (8H, m, α H-Ala ×3, α H-Lys, α H-Glu, α H-lactic acid, OCH2CHCH2), 3.93 (1H, d, H6a, J = 12.2 Hz), 3.85 (1H, t, H2), 3.76-3.79 (1H, dd, H6b), 3.45-3.57 (3H, m, H3, H4, H5), 3.00 (2 H, t, ϵ CH2-Lys), 2.36-2.43 (2H, m, γ CH2-Glu), 2.12-2.18 (1H, m, β CH2-Glu), 1.94-2.03 (4H, m, β CH2-Glu, NHAc), 1.67-1.82 (4H, m, β, δ-CH2-Lys), 1.37-1.45 (14H, m, CH3-lactic acid, γ CH2-Lys, CH3-Ala × 3) 13C NMR (75 MHz, D2O): 177.88, 175.98, 175.93, 175.31, 175.22, 174.92, 174.83, 174.26, 133.52 (OCH2CHCH2), 118.23 (OCH2CHCH2), 100.27 (C1), 82.98, 75.78, 68.84 (C3, C4, and C5), 70.66 (OCH2CHCH2), 60.86 (C6), 55.29, 54.30, 52.89, 50.14, 49.95, 49.60 (α-Cs), 39.30 (ϵ CH2-Lys), 31.46 (γ CH2-Glu), 30.25 (β CH2-Glu), 26.51 (β CH2-Lys), 22.34, 22.21 (δ CH2-Lys, NHCH3), 18.91, 16.68, and 16.36. HRMS-MALDI-TOF calc. for C34H59N9O13 (M + Na): 824.4232, found 824.3087. The compound (10.6 mg, 12.4 μmol) was dissolved in a mixture of ethanol/acetic acid/water (EtOH/HOAc/H2O, 2:1:1, 0.8 ml), and 10% Pd on charcoal (9 mg) was added. After stirring at room temperature for 48 h, the reaction mixture was filtered. The filtrate was concentrated under reduced pressure, and the residue was coevaporated from toluene (3 × 20 ml). The residue was subjected to Sephadex G15 size exclusion column chromatography to give the target compound 6 as a mixture of α/β anomers (8.6 mg, 91%). 1H NMR (500 MHz, D2O): δ 5.04 (0.60H, d, H1-α anomer, J = 3.3 Hz), 4.56 (0.39H, d, H-1-β-anomer, J = 8.4 Hz), 4.17-4.08 (6H, m, α H-Lys, α H-Glu, α H-Ala × 3, α H-3-propionic acid), 3.36-3.86 (6H, m, H2, H3, H4, H5, and H6), 2.87 (2H, t, ϵ CH2-Lys), 2.21-2.29 (2H, m, γ CH2-Glu), 2.19-2.03 (1H, m, β CH2-Glu), 1.82-1.87 (4H, m, CH2-Glu, NHAc), 1.54-1.67 (4H, β, δ-CH2-Lys), 1.37-1.45 (14H, m, γ CH2-Lys, CH3-lactic acid, CH3-Ala × 3). 13C NMR (75 MHz, D2O) 177.89, 176.14, 175.94, 175.32, 175.21, 174.93, 174.82, 174.38, 174.13, 95.07 (C1-α), 91.13 (C1-β), 82.78, 79.87, 78.24, 77.90, 75.87, 71.65, 69.03, 68.81, 60.87, 60.68, 56.33, 54.30, 53.86, 52.89, 50.13, 49.96, 49.61, 39.30 (ϵ CH2-Lys), 31.42 (γ CH2-Glu), 30.26, 27.08, 26.51, 22.38, 22.22, 22.15, 18.81, 16.73, 16.68, and 16.37. HRMS-MALDI-TOF calc. for C31H55N9O13 (M + Na): 784.8213, found 784.5895. Compounds 5 and 6 were synthesized using similar protocol whereby suitable amino acids were chosen depending on the desired target. Analytical data for the glycopeptides is listed below. MTrP_Lys (5Van Amersfoort E.S. Van Berkel T.J.C. Kuiper J. Clin. Microbiol. Rev. 2003; 16: 379-414Crossref PubMed Scopus (619) Google Scholar)—Yield 47%, 1H NMR (500 MHz, D2O): δ = 5.04 (0.45H, d, H1-α anomer, J = 3.5 Hz), 4.55 (0.54H, d, H-1-β-anomer, J = 8.0 Hz), 4.10-4.17 (5H, m, α H-Lys, α H-Glu, α H-Ala × 2, α-H-lactic acid), 3.34-3.81 (6H, m, H2, H3, H4, H5, and H6), 2.88 (2H, t, ϵ CH2-Lys), 2.25-2.28 (2H, m, γ CH2-Glu), 2.10 (1H, m, β CH2-Glu), 1.82-1.91 (4H, m, CH2-Glu, NHAc), 1.54-1.72 (4H, β, δ-CH2-Lys), and 1.25-1.37 (11H, m, γ CH2-Lys, CH3-lactic acid, CH3-Ala × 2). 13C NMR (HSQC, D2O) 95.07 (C1-α), 91.47 (C1-β), 82.99, 80.06, 78.20, 75.81, 73.92, 71.95, 69.29, 60.91, 54.39, 53.99, 52.93, 39.34 (ϵ CH2-Lys), 31.63 (γ CH2-Glu), 30.83, 27.10, 26.97, 26.57, 22.98, 22.19, 18.93, 16.71, and 16.41. HRMS-MALDI-TOF calc. for C28H50N8O12 (M + Na): 713.3548, found 713.4080. MTP_Lys (4Beutler B. Mol. Immunol. 2004; 40: 845-859Crossref PubMed Scopus (886) Google Scholar)—Yield 61%, 1H NMR (500 MHz, D2O): δ 5.16 (0.69H, d, H1-α-anomer, J = 3.3 Hz), 4.67 (0.31H, d, H1-β-anomer, J = 8.1 Hz), 4.20-4.34 (4H, m, α-H, Lys, α-H, Glu, α-H, Ala, α-H, lactic acid), 3.50-4.00 (6H, m, H2, H3, H4, H5, and H6), 3.01 (2H, t, ϵ-CH2, Lys), 2.39-2.45 (2H, m, γ-CH2, Glu), 2.15-2.23 (1H, m, β-CH2, Glu), 1.65-2.00 (8H, m, β-CH2, Glu, β, δ-CH2, Lys, NHCOCH3), and 1.37-1.47 (8H, m, γ-CH2, Lys, CH3, lactic acid, CH3, Ala). 13C NMR (75 MHz, D2O) 177.06, 176.02, 175.25, 174.14, 95.07 (C1-β), 91.13 (C1-α), 82.77, 79.85, 78.46, 78.24, 77.89, 75.87, 73.51, 71.66, 69.05, 60.88, 60.67, 56.34, 53.86, 53.63, 52.87, 49.98, 49.03, 39.33 (ϵ-CH2, Lys), 31.57 (γ-CH2, Glu), 30.53, 26.93, 26.42, 22.65, 22.37, 22.28, 22.15, 18.79, and 16.70. HRMS-MALDI-TOF calc. for C25H45N7O11 (M + Na): 642.3067, found 642.3777. The DAP containing muramyl tripeptides 7-9 were synthesized similarly to procedures described above whereby the Lys(Mtt)-OH was replaced by a suitable protected DAP derivative (38Chowdhury A.R. Boons G.J. Tetrahedron Lett. 2005; 46: 1675-1678Crossref Scopus (49) Google Scholar) (38.7 mg, 42 μmol) to afford the desired protected DAP derivative. Once cleaved from the resin, the DAP-PGNs were treated with 20% trifluoroacetic acid to deprotect the tert Butoxycarbonyl and tert butyl protecting groups on the side chain of the DAP. The deprotected derivative was precipitated from cold diethyl ether to afford an off-white compound. To a solution of this compound in EtOH:H2O:1 (n) HCl (4:2:0.01, 0.6 ml), 10% Pd/C (5 mg) was added and stirred at room temperature for 16 h. The solution was filtered and purified by Sephadex G10 size exclusion column chromatography to afford the target compound as a mixture of α/β anomers (9.3 mg, 30% overall). MTP_DAP (7Lien E. Ingalls R.R. Crit. Care Med. 2002; 30 (-S11): S1Crossref PubMed Scopus (252) Google Scholar)—1H NMR (500MHz, D2O): δ 5.08 (0.16H, d, H1-α-anomer), 4.32 (0.84H, d, H1-β-anomer, J = 8.4Hz), 4.07-4.23 (5H, m, α-H × 2, DAP, α-H, Ala, α-H, Glu, α-H, lac), 3.67-3.89 (3H, m, H2, H6ab), 3.38-3.50 (3H, m, H3, H4, and H5), 2.27-2.36 (2H, m, γ-CH2, Glu), 2.10 (1H, m, β-CHH, Glu), 1.65-1.93 (8H, m, β, δ-CH2, DAP, β-CHH, Glu, NHCOCH3), 1.42-1.45 (2H, m, γ-CH2, DAP), and 1.29-1.35 (6H, m, CH3, Lac, CH3, Ala). 13C (HSQC): 102.18 (C1-β), 91.74 (C1-α), 83.31, 78.93, 76.24, 69.16, 60.66 (C6), 60.65, 60.06, 58.04, 55.68, 55.01, 54.33, 53.66, 50.29, 32.09 (γ-C, Glu), 30.75 (C-DAP), 27.71 (β-C, Glu), 23.00 (NHCOCH3), 21.98, 19.29, and 17.27. HRMS-MALDI-TOF calc. for C25H45N7O11 (M + HCl): 700.1355, found 700.4058. MTrP_DAP (8O'Neill L.A.J. Science. 2004; 303: 1481-1483Crossref PubMed Scopus (71) Google Scholar)—1H NMR (600MHz, D2O): δ 5.19 (0.16H, bs, H1), 4.48 (0.84H, d, H1, J = 7.2Hz), 4.23-4.39 (6H, m, α-H, e-H, DAP, α-H × 2, Ala, α-H, Glu, α-H, lac), 3.51-3.98 (6H, m, H2, H6, H3, H4, and H5), 2.40 (2H, m, γ-CH2, Glu), 2.13-2.14 (1H, m, β-CHH, Glu), 1.78-2.09 (8H, m, β,δ-CH2, DAP, β-CHH, Glu, NHCOCH3), and 1.38-1.50 (11H, m, γ-CH2, DAP, CH3, Lac, CH3 × 2, Ala). 13C (HSQC): 102.13 (C1-β), 91.65 (C1-α), 81.82, 78.70, 77.49, 76.28, 72.13, 69.36, 61.22 (C6), 60.01, 59.15, 57.59, 57.42, 55.68, 54.79, 54.30, 53.13, 53.95, 49.97, 31.78 (γ-C, Glu), 30.87 (C-DAP), 27.81 (β-C, Glu), 22.92 (NHCOCH3), 21.24, 19.25, 18.95, 18.03, and 16.81. HRMS-MALDI-TOF calc. for C25H45N7O11 (M + HCl): 771.2135, found 771.8770. MPP_DAP (9Check W. Asm News. 2004; 70: 317-322Google Scholar)—1H NMR (500MHz, D2O): δ 5.16 (0.41H, bs, H1), 4.40 (0.58 H, d, H1, J = 9.0 Hz), 4.22-4.29 (7H, m, α-H, e-H, DAP, α-H × 3, Ala, α-H, Glu, α-H, lac), 3.50-3.98 (6H, m, H2, H6, H3, H4, and H5), 2.39 (2H, m, γ-CH2, Glu), 2.13-2.15 (1H, m, β-CHH, Glu), 1.90-2.03 (8H, m, β,δ-CH2, DAP, β-CHH, Glu, NHCOCH3), and 1.38-1.57 (14H, m, γ-CH2, DAP, CH3, Lac, CH3 × 3, Ala). 13C (HSQC): 102.39 (C1-β), 91.66 (C1-α), 83.35, 80.13, 78.52, 78.25, 76.11, 72.08, 69.40, 60.95 (C6), 60.88, 60.60, 57.40, 55.59, 54.61, 54.40, 53.77, 53.01, 50.01, 31.60, 30.48 (C-DAP), 27.05, 22.40 (NHCOCH3), 21.01, 19.06, and 16.83. HRMS-MALDI-TOF calc. for C25H45N7O11 (M + HCl): 842.2914, found 842.6710. The biospecific interaction analysis was performed using BIAcore 3000 biosensor system (Biacore Inc., Uppsala, Sweden). The CM-5 research grade sensor chip, HBS-EP buffer, and immobilization reagents (1-ethyl-3-(3-N,N-dimethylaminopropyl)carbodiimide (EDC), N-hydroxy succinimide (NHS), and ethanolamine) were obtained from BIAcore Inc. phosphate-buffered saline buffer was purchased from Sigma, and MDP was purchased from Calbiochem. All solutions were filtered using a 0.22-μm PES membrane syringe filter and degassed prior to use. PGRP-IαC was covalently immobilized by a standard amine coupling procedure using the amine coupling kit supplied by the manufacturer. A fixed flow rate of 10 μl/min was used throughout the immobilization procedure with HBS-EP (pH 7.4, 0.01 m HEPES, 150 mm NaCl, 3 mm EDTA, 0.005% P20) as the running buffer. The surface was activated using 70 μl of freshly mixed 1:1 100 mm NHS and 391 mm EDC for 7 min. Upon activation, a 60 μg/ml solution of PGRP-Iα in 10 mm NaOAc (pH 4.5) was injected for 8 min. The remaining active esters on the surface were quenched using 70 μl of 1.0 m ethanolamine (pH 8.5) for 7 min. A ligand density of ∼10,000 RU was achieved. Blocking of a control flow cell was accomplished by activation followed by an immediate quenching of the flow cell as described above. PGRP-S immobilization was accomplished using the same protocol as above with a change to 5 mm maleate buffer (pH 6.0) as the immobilization buffer. A ligand density of ∼5,000 RU was achieved after 8 min of protein injection. Although a higher initial immobilization density was targeted, longer PGRP-S injections resulted in no change of protein density. Initial binding studies of the DAP containing compounds with PGRP-S suggested high affinity prompting the formation of a low density immobilization surface for kinetic analysis. A similar protocol was used with an injection of PGRP-S solution of 50 μg/ml in 10 mm NaOAc (pH 4.5) for 5 min to afford an immobilized surface of 2,700 RU. For the binding studies, fixed flow rates of 5 μl/min for association and dissociation with a constant temperature of 25 °C were employed. The association and dissociation times were 5 min and 10 min, respectively. These surfaces had greater than 90% reproducibility if used within a 3- to 4-day period. PGRP Iα: phosphate-buffered saline buffer (pH 7.4, 0.01 m phosphate, 138 mm NaCl, 2.7 mm KCl) was selected as both the running and dissociation buffer. The lysine containing analytes, pentapeptide (Lys-PP 1), muramyldipeptide (MDP 3), muramyltripeptide (MTP 4), muramyltetrapeptide (MTrP 5), and muramylpentapeptide (MPP 6), were passed over the surface at a concentration range from 20 to 60 μm using the kinetic wizard method. The surface did not require a regeneration injection for the Lys-PP, MDP, or MTP. For MTrP and MPP, a regeneration injection of 0.01% Tween-20 in water for 20 s at a flow rate of 30 μl/min followed by 15 min of stabilization time was required to achieve prior baseline status. The DAP-containing analytes, DAP-PP (2), MTP-DAP (7), MTrP-DAP (8), and MPP-DAP (9), were passed over the surface at concentrations ranging from 10 to 50 μm. For MTrP-DAP and MPP-DAP, the regeneration was performed as described for the lysine-containing fragments. For PGRP-S, HBS-EP buffer was selected as both the running and dissociation buffers. Due to a greater variation in binding affinity, optimum concentration ranges for each analyte were established. For the lysine-containing compounds, MTP was examined from 500 to 1000 μm, MTrP from 200 to 500 μm, and MPP from 50 to 300 μm. Initial binding studies were conducted on a flow channel with 5000 RU density. The DAP-containing muramyl peptides showed high affinity biding with on and off rates in the measurable range for kinetic analysis. These studies were conducted on a flow channel containing 2700 RU of PGRP-S to minimize rebinding and mass transport effect. A concentration range of 10-1000 nm was selected for MPP-DAP and MTrP-DAP and for MTP-DAP, a concentration range of 100-1000 nm was selected. The kinetic studies were performed using wizard kinetic software with a flow rate of 10 μl/min and association and dissociation times of 5 and 10 min, respectively. The surface was regenerated by a 60-s injection of 10 mm NaOH, pH 11.4, at a flow rate of 30 μl/min. The responses near equilibrium (Req) for the comparative affinity and rate constants k1 and k-1 for kinetic analysis were obtained by fitting the primary sensogram data using the BIAevaluation 3.1 software. The dissociation rate constant is derived using, Rt=Rt0e−k−1(t−t0) where Rt0 is the amplitude of the initial response, and k-1 is the dissociation rate constant. The association rate constant k1 can be derived from the measured k-1 values, using, Rt=Rmax[1−e−(k1C+k−1)(t−t0) where Rt is response at time t, Rmax is the maximum response, C is concentration of the analyte in the solution, and k1 and k-1 are association and dissociation rate constants, respectively. The ratio of k1 and k-1 yields the value of association constant KA (k1/k-1). The interactions of human PGRP-IαC and PGRP-S with a range of synthetic lysine- and DAP-containing PGN fragments were probed using surface plasmon resonance (SPR). SPR is a rapid and sensitive method for the evaluation of affinities of bimolecular interactions (39Jonsson U. Fagerstam L. Ivarsson B. Johnsson B. Karlsson R. Lundh K. Lofas S. Persson B. Roos H. Ronnberg I. S" @default.
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• W2141766281 date "2005-11-01" @default.
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• W2141766281 title "Selective Recognition of Synthetic Lysine and meso-Diaminopimelic Acid-type Peptidoglycan Fragments by Human Peptidoglycan Recognition Proteins Iα and S" @default.
• W2141766281 cites W1514224413 @default.
• W2141766281 cites W1970190307 @default.
• W2141766281 cites W1972053181 @default.
• W2141766281 cites W1972285445 @default.
• W2141766281 cites W1980927664 @default.
• W2141766281 cites W1987588217 @default.
• W2141766281 cites W1989984780 @default.
• W2141766281 cites W1991894986 @default.
• W2141766281 cites W1993037429 @default.
• W2141766281 cites W1994599007 @default.
• W2141766281 cites W2000530029 @default.
• W2141766281 cites W2000667679 @default.
• W2141766281 cites W2002225831 @default.
• W2141766281 cites W2003634035 @default.
• W2141766281 cites W2006768051 @default.
• W2141766281 cites W2016143376 @default.
• W2141766281 cites W2020664730 @default.
• W2141766281 cites W2020969008 @default.
• W2141766281 cites W2021389098 @default.
• W2141766281 cites W2024974737 @default.
• W2141766281 cites W2029845836 @default.
• W2141766281 cites W2033368676 @default.
• W2141766281 cites W2040024879 @default.
• W2141766281 cites W2055022595 @default.
• W2141766281 cites W2059145665 @default.
• W2141766281 cites W2074636100 @default.
• W2141766281 cites W2092459631 @default.
• W2141766281 cites W2097042447 @default.
• W2141766281 cites W2101772709 @default.
• W2141766281 cites W2113474003 @default.
• W2141766281 cites W2113769407 @default.
• W2141766281 cites W2125309974 @default.
• W2141766281 cites W2130946949 @default.
• W2141766281 cites W2131392583 @default.
• W2141766281 cites W2133449490 @default.
• W2141766281 cites W2136986799 @default.
• W2141766281 cites W2139867627 @default.
• W2141766281 cites W2140289284 @default.
• W2141766281 cites W2150771431 @default.
• W2141766281 cites W2151020563 @default.
• W2141766281 cites W2155493873 @default.
• W2141766281 cites W2949160274 @default.
• W2141766281 cites W4366064347 @default.
• W2141766281 doi "https://doi.org/10.1074/jbc.m506385200" @default.
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