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• W2024967076 abstract "Ovocleidin-17 (OC17) from Gallus gallus is one of the best candidates to control and regulate the deposition of calcium carbonate in the calcified eggshell layer. Here, the crystal structure of monomeric OC17, determined at a resolution of 1.5 Å, was refined to a crystallographic R-factor of 20.1%. This is the first protein directly involved in a non-pathological biomineralization process resolved by x-ray diffraction to date. The protein has a mixed α/β structure containing a single C-type lectin-like domain. However, although OC17 shares the conserved scaffold of the C-type lectins, it does not bind carbohydrates. Nevertheless, in vitro OC17 modifies the crystalline habit of calcium carbonate (CaCO3) and the pattern of crystal growth at intervals of 5–200 μg/ml. Determining the three-dimensional structure of OC17 contributes to a better understanding of the biological behavior of structurally related biomolecules and of the mechanisms involved in eggshell and other mineralization processes. Ovocleidin-17 (OC17) from Gallus gallus is one of the best candidates to control and regulate the deposition of calcium carbonate in the calcified eggshell layer. Here, the crystal structure of monomeric OC17, determined at a resolution of 1.5 Å, was refined to a crystallographic R-factor of 20.1%. This is the first protein directly involved in a non-pathological biomineralization process resolved by x-ray diffraction to date. The protein has a mixed α/β structure containing a single C-type lectin-like domain. However, although OC17 shares the conserved scaffold of the C-type lectins, it does not bind carbohydrates. Nevertheless, in vitro OC17 modifies the crystalline habit of calcium carbonate (CaCO3) and the pattern of crystal growth at intervals of 5–200 μg/ml. Determining the three-dimensional structure of OC17 contributes to a better understanding of the biological behavior of structurally related biomolecules and of the mechanisms involved in eggshell and other mineralization processes. The avian eggshell is a highly ordered nanocomposite structure that is deposited in an acellular milieu. It is secreted by the distal part of the oviduct, the uterus, and isthmus, and it is in the latter that the inner and the outer shell membranes are produced (1Roberts J.R. Brackpool C.E. Poult. Sci. Rev. 1994; 5: 245-272Google Scholar). During the transition in the isthmus (tubular shell gland) and the uterus, spherulitic crystal growth is initiated by the deposition of calcium carbonate onto specific protein aggregates that are the precursors of the mammillary knobs (2Nys Y. Hincke M.T. Arias J.L. Garcia-Ruiz J.M. Solomon S.E. Poult. Avian. Biol. Rev. 1999; 10: 143-166Google Scholar). Indeed, some of the most important macromolecules that regulate the nucleation and crystal growth of calcite are present in these knobs. Thereafter, the bulk of the calcite is deposited in the uterus, a process that is controlled by competitive crystal growth and that gives rise to the cone and palisade layers (3, Garcia-Ruiz, J. M. & Rodriguez-Navarro, A. B. (1994). in 7th International Symposium on Biomineralization. (Allemand, D. & Cuif, J-P., eds) pp. 85, Bulletin de l'Institut océanographique, Numéro spécial 14, 1. MonacoGoogle Scholar). As a result, two preferred crystallographic orientations are generated and reach a maximum toward the surface of the palisade layer (4Silyn-Roberts H. Sharp R.M. Proc. R. Soc. Lond. B Biol. Sci. 1986; 227: 303-324Crossref Google Scholar). A complex array of proteins exists in the uterine fluid and eggshell extract of Gallus gallus. Although one family of matrix proteins corresponds to the egg white proteins:lysozyme (14.4 kDa), ovotransferrin (78 kDa), and ovalbumin (43 kDa; Refs. 5Hincke M.T. Gautron J. Panheleux M. Garcia-Ruiz J.M. McKee M.D. Nys Y. Matrix Biol. 2000; 19: 443-453Crossref PubMed Scopus (204) Google Scholar, 6Hincke M.T. Connect. Tissue Res. 1995; 31: 227-233Crossref PubMed Scopus (104) Google Scholar), another group of proteins in the eggshell is the bone matrix proteins osteopontin and sialoprotein (7Solomon S. Br. Poultry. Sci. 1999; 40: 5-11Crossref PubMed Scopus (14) Google Scholar). Finally, the third group of proteins that is specifically found in the uterus includes the ovocleidins and ovocalyxins. Indeed, ovocleidin-116 has been cloned and corresponds to the core protein of an eggshell dermatan sulfate proteoglycan (8Hincke M.T. Gautron J. Tsang C.P. McKee M.D. Nys Y. J. Biol. Chem. 1999; 274: 32915-32923Abstract Full Text Full Text PDF PubMed Scopus (137) Google Scholar). The intramineral protein ovocleidin-17 (OC17) 1The abbreviations used are: OC17, ovocleidin-17; RMBP, rat mannose-binding protein. 1The abbreviations used are: OC17, ovocleidin-17; RMBP, rat mannose-binding protein. is an abundant component of the soluble fraction, and it is also glycosylated (OC23, Ref. 9Mann K. FEBS Lett. 1999; 463: 12-14Crossref PubMed Scopus (47) Google Scholar). This protein can be obtained by acidic extraction of the G. gallus eggshell, and when sequenced it was shown to contain 142 amino acids including two phosphorylated serines (10Mann K. Siedler F. Biochem. Mol. Biol. Int. 1999; 47: 997-1007PubMed Google Scholar). Based on this amino acid sequence, OC17 was seen to contain a C-type lectin-like domain (11Drickamer K. Curr. Opin. Struct. Biol. 1999; 9: 585-590Crossref PubMed Scopus (528) Google Scholar) similar to lithostathine in human pancreatic stones (12Bertrand J.A. Pignol D. Bernard J.P. Verdier J.M. Dagorn J.C. Fontecilla-Camps J.C. EMBO J. 1996; 15: 2678-2684Crossref PubMed Scopus (79) Google Scholar) and perlucin of the nacreous layer of Haliotis laevigata shell (13Mann K. Weiss I.M. André S. Gabius H.-J. Fritz M. Eur. J. Biochem. 2000; 267: 5257-5264Crossref PubMed Scopus (152) Google Scholar, 14Weiss M. Kaufmann S. Mann K. Fritz M. Biophys. Biochem. Res. Comm. 2000; 267: 17-21Crossref PubMed Scopus (202) Google Scholar). Notably, all of these C-type lectin-like domain-containing proteins are associated with the mineral phase of calcium carbonate. OC17 is the major protein component of the eggshell matrix and one of the best candidates to regulate mineral deposition. However, the binding of carbohydrates in a Ca2+-dependent manner typical of C-type lectins has not been attributed to this protein. OC17 is remarkably well conserved in the eggshell matrix of a number of avian species, suggesting that it plays a fundamental role in the process of eggshell formation (15Panheleux M. Bain M. Fernández M.S. Morales I. Gautron J. Arias J.L. Solomon S.E. Hincke M. Nys Y. Br. Poultry. Sci. 1999; 40: 240-252Crossref PubMed Scopus (120) Google Scholar). Indeed, a specific antiserum against OC17 shows that it is present in the mammillary knobs, the palisade layer, and in the tubular gland cells of the shell gland (16Hincke M.T. Tsang C.P.W. Courtney M. Hill V. Narbaitz R. Calcif. Tissue Int. 1995; 56: 578-583Crossref PubMed Scopus (126) Google Scholar). Our aim is to gain a better understanding of the mechanisms underlying the phenomena of CaCO3 biomineralization, which may be useful when considering the possible biomimetical applications. With this in mind, we have centered our efforts on studying the proteins that play an important role in crystal growth during the eggshell formation. Here, for the first time, we describe the three-dimensional structure of a non-pathological protein involved in a biomineralization process, OC17. In addition, we developed a preliminary model of the protein-calcite interaction based on our scanning electron and atomic force microscopy observations. Crystallization and Data Collection—Ovocleidin-17 was purified and crystallized as described by Reyes-Grajeda et al. (17Reyes-Grajeda J.P. Jáuregui-Zúñiga D. Rodríguez-Romero A. Hernández-Santoyo A. Bolanos-Garcia V.M. Moreno A. Protein Pept. Lett. 2002; 9: 253-257Crossref PubMed Scopus (15) Google Scholar). Crystals of OC17 were grown at 4 °C by sitting droplet vapor diffusion. The protein solution, 5 μl of 6 mg ml-1, was added to 5 μl of reservoir buffer (6% (w/v) polyethylene glycol 4000, 0.1 m sodium acetate, pH 4.6), and the droplets were equilibrated with 1 ml of reservoir buffer. Crystals grew over 10–20 days reaching maximum dimensions of 0.2 × 0.05 × 0.05 mm. A complete data set was collected from a single crystal at a resolution of 1.5 Å at the European Synchrotron Radiation Facility beamline BM14S (Grenoble, France) with a MarCCD detector system using a crystal to a detector distance of 80 mm and a wavelength of 0.97 Å. All data were integrated using the MOSFLM program (18Leslie A.G.W. Acta Crystallogr. Sect. A. 1992; 55: 1696-1702Crossref Scopus (485) Google Scholar) and then reduced with SCALE and TRUNCATE (19Number Collaborative Computational Project Acta Crystallogr. Sect. D. 1994; 50: 760-763Crossref PubMed Scopus (19748) Google Scholar), yielding a unique data set of 26,123 reflections with a Rmerge factor of 6.3%. The crystals belonged to the P3221 space group with one monomer/asymmetric unit corresponding to a 45% (v/v) solvent content. The data collection parameters and statistics are presented in Table I.Table IData collection and refinement statisticsData collectionSpace groupP3221Unit cell parameters (Å)a = b = 58.26, c = 82.46Resolution limit (Å)1.5Specific volume2.38Number of molecules in the asymmetric unit1Number of unique reflections26,123Completeness (%, last shell)99.5 (98.5)RmergeaRmerge = Σ|Ihkl - 〈Ihkl〉|/ ΣIhkl6.3Crystallographic refinementResolution range (Å)7.98-1.5Number of reflections26,123RfactorbRfactor = Σhkl ‖Fo| - |Fc‖/Σhkl|Fo| for all data except 10%, which was used for the Rfree calculation (%)0.20Rfree (%)0.218Number of non-H protein atoms1046Number of water molecules153Root mean square deviations from ideal valuesBond lengths (Å)0.005Bond angles (°)1.3Dihedral angles (°)22.7Improper angles (°)3.94a Rmerge = Σ|Ihkl - 〈Ihkl〉|/ ΣIhklb Rfactor = Σhkl ‖Fo| - |Fc‖/Σhkl|Fo| for all data except 10%, which was used for the Rfree calculation Open table in a new tab Structure Determination and Refinement—The structure of the native OC17 crystal was solved by molecular replacement with the AMoRe (20Navaza J. Acta Crystallogr. Sect. A. 1994; 50: 157-163Crossref Scopus (5028) Google Scholar) program using data up to 3.5 Å. The search model was derived from the human pancreatic stones lithostathine (1lit) at 1.55 Å resolution. The rotational search showed two solutions with relatively low correlation values of 2.8 and 2.4σ. A translational search and rigid body fitting for these two solutions produced a correlation value of 0.28 (R-value of 48.1%) over 0.15 for the next highest peak. This solution was applied to the model, and the resulting coordinates were then used for refinement. The initial model, oriented and positioned according to the molecular replacement solution, was examined using the program TURBO/FRODO (21Jones T.A. J. Appl. Cryst. 1978; 11: 268-272Crossref Google Scholar). To improve the model, rounds of model building and iterative simulated annealing were performed using torsion angle dynamics (starting at T = 5000 K with a cooling rate of 50 K/cycle), energy minimization, and B-factor refinement using CNS tasks (22Brunger A.T. Adams P.D. Clore G.M. DeLano W.L. Gros P. Grosse-Kunstleve R.W. Jiang J.-S. Kuszewski J. Nilges N. Pannu N.S. Read R.J. Rice L.M. Simonson T. Warren G.L. Acta Crystallogr. Sect. D. 1998; 54: 905-921Crossref PubMed Scopus (16957) Google Scholar). At this point the model still had ambiguous zones (Rwork 41.2%, Rfree 46.6%, with ∼10% of reflections in the test set for cross validation). The refinement started at a resolution of 2.5 Å with temperature factors for all atoms set to 20 Å2. By increasing the resolution stepwise, the model was refined to a resolution of 1.5 Å. The combination of crystallographic refinement and model building improved the initial model, solving the ambiguities. Water molecules were automatically inserted using CNS and accepted if the corresponding Fo - Fc density map was at least 3.0σ and the geometric requirements for hydrogen bonding were fulfilled. Finally, one phosphate group was modeled and refined to fit the extra electron density found in the vicinity of Ser61. The crystallographic R-factor of the model is 20.1% for all unique reflections at a 1.5-Å resolution (Rfree = 21.8%). Crystal Growth Experiments—Crystallization experiments were carried out at 18 °C inside an ad hoc designed chamber for the synthesis of CaCO3 crystals. This system maintains the same CO2 vapor pressure generated by the decomposition of ammonium carbonate (25 mm). The chamber is composed of a dual-glass Petri dish in which one of the compartments holds several glass coverslips onto which the OC17 could be poured. In all the experiments the concentration of CaCl2 was 0.1 m in a volume of 50-μl. For each experiment, different concentrations of OC17 were added to the droplet (5–200 μg/ml). After 3 days the crystals were rinsed with Milli-Q water, air-dried, and prepared for a scanning electron microscopy-energy dispersive x-ray spectroscopy analysis using JEOL JSM9000 LV scanning electron microscopy at 20 kV. Atomic Force Microscopy Studies on OC17 Nanospheres—Samples of aqueous OC17 for tapping mode atomic force microscopy were prepared by adsorbing several microliters of protein solution (1 μg/ml) at room temperature onto freshly cleaved mica. This sample was incubated during 30 min. The surface was then lightly rinsed with double distilled water and dried at room temperature. A Nanoscope-IIIa from DIGITAL Instruments was used for atomic force microscopy acquisition. The atomic force microscopy images were obtained in tapping mode at room temperature in air at a scanning rate of 1.0 Hz for different scan sizes. The installed NanoScope Software (Version 4.42r7) was used to produce three-dimensional color graphics. Structure Determination—We first established the conditions that yielded crystals of OC17 that belonged to the trigonal space group P3221 (a = b = 58.26 Å and c = 82.46 Å) with one molecule in the asymmetric unit. These crystals were used to solve the structure by molecular replacement using the previously reported lithostathine structure as a search probe (12Bertrand J.A. Pignol D. Bernard J.P. Verdier J.M. Dagorn J.C. Fontecilla-Camps J.C. EMBO J. 1996; 15: 2678-2684Crossref PubMed Scopus (79) Google Scholar). In the final model, the first three N-terminal residues Asp1, Pro2, and Asp3 were ill defined and were therefore not incorporated into the model. In addition, the side chains at the surface loop Gly64-Gly68 were also poorly defined in the electron density maps. Nevertheless, the root mean square deviations were 0.005 Å from the ideal bond lengths and 1.3° from the ideal bond angles. Calculations with the program PROCHECK (23Laskowski R.A. Mac Arthur M.W. Moss D.S. Thornton J.M. J. Appl. Cryst. 1993; 26: 283-291Crossref Google Scholar) indicated that almost all residues (93.6%) in the asymmetric unit were located in the most favorable regions, with none of the residues in the disallowed regions. The data collection and refinement statistics are listed in Table I. The crystallized OC17 is 142 amino acids in length and contains a single C-type lectin-like domain (24Zelensky A.N. Gready J.E. Proteins. 2003; 52: 466-477Crossref PubMed Scopus (97) Google Scholar) of 46 × 44 × 38 Å (Fig. 1). The general topology is that of a mixed α/β structure, which is comprised of three α-helices and eight β-strands, the latter being clustered in two oppositely oriented antiparallel β-sheets (β1-β2-β8-β3 and β5-β4-β6-β7). The structure can be divided into two parts. A lower part of the molecule containing the two major helices α1 and α2, which are oriented perpendicular to one another and surround the four β-strands (β1, β2, β8, and β3). The upper half includes the second four-stranded (β5-β4-β6-β7) β-sheet with a short 310 helix connecting strands β5 and β6. The OC17 structure is further stabilized by three disulfide bridges (Fig. 2A), which are conserved in the long-form C-type lectins. 2Available at us.expasy.org/cgi-bin/prosite-search-ac?PDOC00537. Thus, in the lower half of the molecule, the Cys5-Cys16 bridge connects the loop preceding strand β1 with the N terminus of the β2 strand, whereas the other disulfide bond (Cys33-Cys138) joins α1 to β8. In the top half of the molecule, a disulfide bridge between Cys113-Cys130 cross-links strand β6 to the preceding β8 loop.Fig. 2Aspects of the OC17 structure.A,2Fo - Fc electron density map of the Cys5-Cys16 disulfide bridge with a cutoff level of 1.0σ at 1.5 Å resolution. B, final refined 2Fo - Fc electron density, contoured at 1.0σ, around Ser61. The electron density observed in the vicinity of Ser61 was unambiguously pinpointed to a covalently attached phosphoryl molecule. Ser(P)61 is located at the C-terminal end of the α2-helix in the loop connecting α2 with β4 in the lower lobe of the structure. The figure was drawn with TURBO/FRODO (21Jones T.A. J. Appl. Cryst. 1978; 11: 268-272Crossref Google Scholar). The red sphere represents a water molecule.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Given that the major form of OC17 is a phosphoprotein with two phosphorylated serines (Ser61 and Ser67, Ref. 10Mann K. Siedler F. Biochem. Mol. Biol. Int. 1999; 47: 997-1007PubMed Google Scholar), the phosphoryl group density observed in the vicinity of Ser61 was not unexpected. Structurally, the electron density was unambiguously pinpointed to a covalently attached tetrahedral component (Fig. 2B). Ser(P)61 is located at the C-terminal end of the α2-helix in the loop connecting α2 with β4 in the lower lobe of the structure. However, it was not possible to model the potential phosphorylation at Ser67 because of a disordered region in the crystal structure. The phosphoryl group at Ser61 might interact specifically with Ca2+ ions. However, when we soaked OC17 crystals in a solution of calcium chloride to determine specific binding sites, we did not find any changes in density that might correspond to the attachment of Ca2+ ions in a Fo - Fc electron density map. It is possible that the chemical affinity of OC17 is more specific to carbonate than Ca2+ ions, but this hypothesis remains to be tested. Structural Relationship with Other C-type Lectin Domains— The sequence of OC17 was aligned with several proteins associated with crystal growth in a mineral phase, as well as with the rat mannose-binding protein (RMBP) that is the prototype of the C-type lectin fold (Table II). RMBP was the only protein belonging to the short C-type lectin domain with two disulfide bridges (as shown in Table II). In RMBP, the carbohydrate recognition domain consists of a compactly folded region that contains a series of loops stabilized by two Ca2+ ions. Carbohydrate binding occurs directly and is coordinated by one of the Ca2+ ions designated as the principal calcium. Interactions with several side chains via hydrogen bonds produces a structure that selectively binds Ca2+, thereby forming an intimately linked ternary complex of protein, Ca2+, and sugar (25Ng K. Kolatkar A. Park-Snyder S. Feinberg H. Clark D. Drickamer K. Weis W. J. Biol. Chem. 2002; 277: 16088-16095Abstract Full Text Full Text PDF PubMed Scopus (86) Google Scholar). However, OC17 and lithostathine do not conserve the residues implicated in the association with Ca2+. Thus, as a consequence of both sequence and structural differences, the calcium-binding sites in the mannose-binding protein are not present in either OC17 or lithostathine. Indeed, the failure to bind to carbohydrates was demonstrated by means of hemagglutination assays.Table IIAmino acid sequence alignment of OC17 with related proteins ansocalcin (34Lakshminarayanan R. Manjunatha Kini R. Valiyaveettil S. Proc. Natl. Acad. Sci. U. S. A. 2002; 99: 5155-5159Crossref PubMed Scopus (91) Google Scholar), lithostathine (12Bertrand J.A. Pignol D. Bernard J.P. Verdier J.M. Dagorn J.C. Fontecilla-Camps J.C. EMBO J. 1996; 15: 2678-2684Crossref PubMed Scopus (79) Google Scholar), perlucin (13Mann K. Weiss I.M. André S. Gabius H.-J. Fritz M. Eur. J. Biochem. 2000; 267: 5257-5264Crossref PubMed Scopus (152) Google Scholar), and RMBP Conserved residues are highlighted grey (>50% conservation) or black (100% conservation). The six amino acids that bind the main Ca2+ ion in RMBP are indicated with a black triangle. Open table in a new tab When the structure of OC17 was analyzed, the potential calcium-binding site in the 310 helix region, corresponding to residues Ala105–Arg109, was seen to be highly positive charged. This implies that the putative calcium-binding site is lost as a result of repulsive forces, thereby preventing the binding of carbohydrates. Unlike lithostathine, the sequence homology between OC17 and RMBP is very low in this region. Nevertheless, although the sequence identity of 32% between the pancreatic inhibitor of stone formation (lithostathine) and OC17 is relatively low, they share a common tertiary architecture (Fig. 3) with a root mean square deviation for all of the Cα atoms of 0.86 Å. The main structural variability was found in the regions of the loops and turns. Until now the structural data available for this large family has demonstrated a common scaffold with a variety of functions in the C-type lectin-like domain fold, which can bind carbohydrates, proteins, and in-organic substrates (24Zelensky A.N. Gready J.E. Proteins. 2003; 52: 466-477Crossref PubMed Scopus (97) Google Scholar). Hence the familial relationships regarding protein folding may result from convergent evolution and may reflect the specificity for certain minerals and biocomposites. Surface Features and Mechanistic Implications—The electrostatic potential on the surface of OC17 reveals a regular distribution of charged residues and a particularly eye-catching feature is the high degree of polarization at the top of the molecule (Fig. 4A). Accordingly, on one side of the OC17 molecule, the surface of the protein presents an extended solvent-exposed basic stretch including 17 of the 21 basic residues. The concentration of the positive charge in OC17 is distributed mostly in a pseudo ring around the molecule with the greatest extension at the top. This can be seen in a close-up view of successive rotating images of the electrostatic charges in three consecutive positions (rotating 120° each, see Fig. 4B). Accordingly, this charge distribution intuitively implies the binding of the calcite ionic crystal surface through a periodic array of local binding sites for ions of opposite charge. This assumption is reinforced by the fact that solvent-exposed residues are conserved, as depicted in Fig. 4B, mainly clustered at the top part of the molecule. The high degree of polarization coupled to a unique array of positive charges on its surface strongly supports the idea that binding could be directed through the interaction with carbonate ions. Interestingly, lithostathine has been implicated in the inhibition of the growth and nucleation of calcium carbonate crystals (12Bertrand J.A. Pignol D. Bernard J.P. Verdier J.M. Dagorn J.C. Fontecilla-Camps J.C. EMBO J. 1996; 15: 2678-2684Crossref PubMed Scopus (79) Google Scholar, 26Gerbaud V. Pignol D. Loret E. Bertrand J.A. Berland Y. Fontecilla-Camps J.-C. Canselier J.-P. Gabast N. Verdier J.-M. J. Biol. Chem. 2000; 275: 1057-1064Abstract Full Text Full Text PDF PubMed Scopus (76) Google Scholar) and shows a highly acidic polarized surface distribution (Fig. 4C). In turn, these subtle differences in the location of surface residues may explain the functional differences between OC17 and lithostathine despite the presence of a conserved C-type lectin domain scaffold. Protein-Crystal Interaction, a Preliminary Model—The influence of the purified OC17 upon calcite crystallization was also investigated in vitro, and some of the more representative calcite crystal structures formed in the presence of the OC17 are shown in Fig. 5. As expected, the common rhombohedral habit of calcite crystals was observed in the absence of the protein (Fig. 5a). However, in the presence of OC17 there was a strong aggregation of calcite crystals in a concentration-dependent manner, similar to that observed in the mammillary zone of the G. gallus eggshell (Fig. 5b). Indeed, the fact that OC17 is found in the mammillary knob could explain the aggregation of calcite crystals in the presence of OC17 in vitro. Using atomic force microscopy techniques, we showed that the aggregation of the protein into nanospheres (Fig. 6) might promote the formation of nucleation centers that would directly influence the aggregation of calcite crystals. This is a similar phenomenon to the model proposed for the amelogenin proteins involved in the biomineralization of dental enamel (27Moradian-Oldak J. Tan J. Fincham A.G. Biopolymers. 1998; 46: 225-238Crossref PubMed Scopus (108) Google Scholar, 28Fincham A.G. Moradian-Oldak J. Simmer J.P. J. Struct. Biol. 1999; 126: 270-299Crossref PubMed Scopus (495) Google Scholar).Fig. 6Three-dimensional view of atomic force micrographs obtained in tapping mode in air of OC17 adsorbed onto a mica surface in a 500 × 500-nm field (a) and a 250 × 250-nm field (b). The atomic force microscopy images show the aggregation of the protein into nanospheres that might promote the formation of nucleation centers and would directly influence the aggregation of calcite crystals.View Large Image Figure ViewerDownload Hi-res image Download (PPT) Because of the large extent of the surface of OC17 that is positively charged and the aggregates that tend to form, it may be possible that large surfaces are exposed to interactions with carbonate ions or with specific crystal lattices of calcite. Hence, we propose a preliminary CaCO3 protein-CaCO3 interaction model, where nanospheres are responsible for the control and nucleation of crystals. However, we cannot discard the influence of synergistic interactions and other macromolecular constituents, although this would have to be tested to fully understand the process of eggshell biomineralization and draw inferences regarding the function of similar proteins in other biological systems. Concluding Remarks—It is becoming very important to search for new strategies to understand the mechanisms and the biomolecules that are involved in the crystallization process of the eggshell formation. The implications of this knowledge are important from the biomedical point of view, as they can be extended to processes as critical as the formation of pancreatic and kidney stones, as well as arterial calcification and cardiovascular disease. On the basis of the information that we have gleaned so far, certain aspects of the mechanism involved can be inferred. We now intend to focus our attention on characterizing those genes involved in regulating the expression of OC17 and other proteins related to the biomineralization of calcite in eggshells. With this information, the existence of these genes in different avian species can be determined, not only to understand their evolution but also, coupled to what we already know, to draw some correlation between structure, function, and evolution." @default.
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• W2024967076 title "Crystal Structure of Ovocleidin-17, a Major Protein of the Calcified Gallus gallus Eggshell" @default.
• W2024967076 cites W1563484889 @default.
• W2024967076 cites W1880245975 @default.
• W2024967076 cites W1969222787 @default.
• W2024967076 cites W1975453400 @default.
• W2024967076 cites W1984314191 @default.
• W2024967076 cites W1986191025 @default.
• W2024967076 cites W1990802145 @default.
• W2024967076 cites W1995017064 @default.
• W2024967076 cites W2001228099 @default.
• W2024967076 cites W2001641653 @default.
• W2024967076 cites W2011300789 @default.
• W2024967076 cites W2028231353 @default.
• W2024967076 cites W2037257086 @default.
• W2024967076 cites W2037951645 @default.
• W2024967076 cites W2047917762 @default.
• W2024967076 cites W2051336083 @default.
• W2024967076 cites W2064528465 @default.
• W2024967076 cites W2068521700 @default.
• W2024967076 cites W2078248419 @default.
• W2024967076 cites W2080476827 @default.
• W2024967076 cites W2082458880 @default.
• W2024967076 cites W2082546129 @default.
• W2024967076 cites W2093329141 @default.
• W2024967076 cites W2099243347 @default.
• W2024967076 cites W2125098863 @default.
• W2024967076 cites W2137006225 @default.
• W2024967076 cites W2169092641 @default.
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