Matches in SemOpenAlex for { <https://semopenalex.org/work/W2048588733> ?p ?o ?g. }
- W2048588733 endingPage "79" @default.
- W2048588733 startingPage "71" @default.
- W2048588733 abstract "The zinc metalloenzyme porphobilinogen synthase (PBGS) contains several functionally important, but previously unidentified, reactive sulfhydryl groups. The enzyme has been modified with the reversible sulfhydryl-specific nitroxide spin label derivative of methyl methanethiosulfonate (MMTS), (1-oxyl-2,2,5,5-tetramethyl-Δ3-pyrroline-3-methyl)methanethiosulfonate (SL-MMTS) (Berliner, L.J., Grunwald, J., Hankovszky, H.O., & Hideg, K., 1982, Anal. Biochem. 119, 450–455). EPR spectra show that SL-MMTS labels three groups per PBGS subunit (24 per octamer), as does MMTS. EPR signals reflecting nitroxides of different mobilities are observed. Two of the three modified cysteines have been identified as Cys-119 and Cys-223 by sequencing peptides produced by an Asp-N protease digest of the modified protein. Because MMTS-reactive thiols have been implicated as ligands to the required Zn(II), EPR spectroscopy has been used to determine the spatial proximity of the modified cysteine residues. A forbidden (Δm = 2) EPR transition is observed indicating a through-space dipolar interaction between at least two of the nitroxides. The relative intensity of the forbidden and allowed transitions shows that at least two of the unpaired electrons are within at most 7.6 Å of each other. SL-MMTS-modified PBGS loses all Zn(II) and cannot catalyze product formation. The modified enzyme retains the ability to bind one of the two substrates at each active site. Binding of this substrate has no influence on the EPR spectral properties of the spin-labeled enzyme, or on the rate of release of the nitroxides when 2-mercaptoethanol is added. The results indicate that binding of this substrate does not affect the environment of the majority of the nitroxides. This is consistent with our previous proposal that it is the substrate that binds only to the Zn(II) enzyme that provides ligands to the catalytic Zn(II) (Jaffe, E.K., Abrams, W.R., Kaempfen, K.X., & Harris, K.A., 1992, Biochemistry 31, 2113–2123). SL-MMTS readily forms disulfide-linked dimers. The rate of dimer formation is proportional to the hydroxide ion concentration and is independent of both buffer and SL-MMTS concentrations. This suggests a rate-limiting hydrolysis of the S-S bond of SL-MMTS followed by rapid reaction of the liberated thiol with a second molecule of SL-MMTS. Therefore, substantial care is required in the use of SL-MMTS as a protein modification reagent at even slightly alkaline pH values." @default.
- W2048588733 created "2016-06-24" @default.
- W2048588733 creator A5026933296 @default.
- W2048588733 creator A5056752747 @default.
- W2048588733 creator A5056772376 @default.
- W2048588733 creator A5081576631 @default.
- W2048588733 creator A5085408345 @default.
- W2048588733 date "1993-01-01" @default.
- W2048588733 modified "2023-09-26" @default.
- W2048588733 title "Spatial proximity and sequence localization of the reactive sulfhydryls of porphobilinogen synthase" @default.
- W2048588733 cites W1524100537 @default.
- W2048588733 cites W1554023844 @default.
- W2048588733 cites W1587278423 @default.
- W2048588733 cites W1593421540 @default.
- W2048588733 cites W1989514450 @default.
- W2048588733 cites W1998198488 @default.
- W2048588733 cites W2007026237 @default.
- W2048588733 cites W2024364068 @default.
- W2048588733 cites W2036285076 @default.
- W2048588733 cites W2060670164 @default.
- W2048588733 cites W2070311991 @default.
- W2048588733 cites W2071637362 @default.
- W2048588733 cites W2080052515 @default.
- W2048588733 cites W2083786664 @default.
- W2048588733 cites W2222559137 @default.
- W2048588733 cites W2346770505 @default.
- W2048588733 cites W2488170673 @default.
- W2048588733 cites W4240894980 @default.
- W2048588733 doi "https://doi.org/10.1002/pro.5560020107" @default.
- W2048588733 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/2142303" @default.
- W2048588733 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/8382991" @default.
- W2048588733 hasPublicationYear "1993" @default.
- W2048588733 type Work @default.
- W2048588733 sameAs 2048588733 @default.
- W2048588733 citedByCount "23" @default.
- W2048588733 countsByYear W20485887332012 @default.
- W2048588733 countsByYear W20485887332014 @default.
- W2048588733 countsByYear W20485887332015 @default.
- W2048588733 countsByYear W20485887332017 @default.
- W2048588733 countsByYear W20485887332018 @default.
- W2048588733 crossrefType "journal-article" @default.
- W2048588733 hasAuthorship W2048588733A5026933296 @default.
- W2048588733 hasAuthorship W2048588733A5056752747 @default.
- W2048588733 hasAuthorship W2048588733A5056772376 @default.
- W2048588733 hasAuthorship W2048588733A5081576631 @default.
- W2048588733 hasAuthorship W2048588733A5085408345 @default.
- W2048588733 hasBestOaLocation W20485887331 @default.
- W2048588733 hasConcept C111998727 @default.
- W2048588733 hasConcept C112243037 @default.
- W2048588733 hasConcept C121332964 @default.
- W2048588733 hasConcept C169912494 @default.
- W2048588733 hasConcept C178790620 @default.
- W2048588733 hasConcept C181199279 @default.
- W2048588733 hasConcept C185592680 @default.
- W2048588733 hasConcept C187961010 @default.
- W2048588733 hasConcept C41183919 @default.
- W2048588733 hasConcept C44228677 @default.
- W2048588733 hasConcept C46141821 @default.
- W2048588733 hasConcept C521977710 @default.
- W2048588733 hasConcept C55493867 @default.
- W2048588733 hasConcept C71240020 @default.
- W2048588733 hasConcept C8010536 @default.
- W2048588733 hasConceptScore W2048588733C111998727 @default.
- W2048588733 hasConceptScore W2048588733C112243037 @default.
- W2048588733 hasConceptScore W2048588733C121332964 @default.
- W2048588733 hasConceptScore W2048588733C169912494 @default.
- W2048588733 hasConceptScore W2048588733C178790620 @default.
- W2048588733 hasConceptScore W2048588733C181199279 @default.
- W2048588733 hasConceptScore W2048588733C185592680 @default.
- W2048588733 hasConceptScore W2048588733C187961010 @default.
- W2048588733 hasConceptScore W2048588733C41183919 @default.
- W2048588733 hasConceptScore W2048588733C44228677 @default.
- W2048588733 hasConceptScore W2048588733C46141821 @default.
- W2048588733 hasConceptScore W2048588733C521977710 @default.
- W2048588733 hasConceptScore W2048588733C55493867 @default.
- W2048588733 hasConceptScore W2048588733C71240020 @default.
- W2048588733 hasConceptScore W2048588733C8010536 @default.
- W2048588733 hasIssue "1" @default.
- W2048588733 hasLocation W20485887331 @default.
- W2048588733 hasLocation W20485887332 @default.
- W2048588733 hasLocation W20485887333 @default.
- W2048588733 hasLocation W20485887334 @default.
- W2048588733 hasOpenAccess W2048588733 @default.
- W2048588733 hasPrimaryLocation W20485887331 @default.
- W2048588733 hasRelatedWork W1551301565 @default.
- W2048588733 hasRelatedWork W1981652652 @default.
- W2048588733 hasRelatedWork W1987845946 @default.
- W2048588733 hasRelatedWork W1998557908 @default.
- W2048588733 hasRelatedWork W2038062934 @default.
- W2048588733 hasRelatedWork W2082448349 @default.
- W2048588733 hasRelatedWork W2086056683 @default.
- W2048588733 hasRelatedWork W2143028632 @default.
- W2048588733 hasRelatedWork W2334782546 @default.
- W2048588733 hasRelatedWork W2950763618 @default.
- W2048588733 hasVolume "2" @default.
- W2048588733 isParatext "false" @default.
- W2048588733 isRetracted "false" @default.
- W2048588733 magId "2048588733" @default.