Matches in SemOpenAlex for { <https://semopenalex.org/work/W2087161907> ?p ?o ?g. }
- W2087161907 endingPage "15729" @default.
- W2087161907 startingPage "15720" @default.
- W2087161907 abstract "Crystallographic studies of human purine nucleoside phosphorylase (hPNP) with several transition-state (TS) analogues in the immucillin family showed an unusual geometric arrangement of the atoms O-5', O-4', and O(P), the nucleophilic phosphate oxygen, lying in a close three-oxygen stack. These observations were corroborated by extensive experimental kinetic isotope effect analysis. We propose that protein-facilitated dynamic modes in hPNP cause this stack, centered on the ribosyl O-4' oxygen, to squeeze together and push electrons toward the purine ring, stabilizing the oxacarbenium character of the TS. As the N-ribosidic bond is cleaved during the reaction, the pK(a) values of N-7 and O-6 increase by the electron density expelled by the oxygen-stack compression toward the purine ring. Increased electron density in the purine ring improves electrostatic interactions with nearby residues and facilitates the abstraction of a proton from a solvent proton or an unidentified general acid, making the purine a better leaving group, and accelerating catalysis. Classical and mixed quantum/classical molecular dynamics (MD) simulations of the Michaelis complex of hPNP with the substrates guanosine and phosphate were performed to assess the existence of protein-promoting vibrations (PPVs). Analogous simulations were performed for the substrates in aqueous solution. In the catalytic site, the O-5', O-4', and O(P) oxygens vibrate at frequencies of ca. 125 and 465 cm(-1), as opposed to 285 cm(-1) in the absence of hPNP. The hybrid quantum mechanical/molecular mechanical method was used to assess whether this enzymatic vibration pushing the oxygens together is coupled to the reaction coordinate, and thus has a direct positive impact on catalysis. The potential energy surface for the phosphorolysis reaction for several snapshots taken from the classical MD simulation showed substantial differences in oxygen compression. Our calculations showed the existence of PPVs coupled to the reaction coordinate, which effect electronic alterations in the active site by pushing the three oxygen centers together in proximity, and accelerate substrate turnover in the phosphorolysis reaction catalyzed by hPNP." @default.
- W2087161907 created "2016-06-24" @default.
- W2087161907 creator A5018522950 @default.
- W2087161907 creator A5019353843 @default.
- W2087161907 creator A5078283384 @default.
- W2087161907 creator A5079231031 @default.
- W2087161907 date "2004-11-05" @default.
- W2087161907 modified "2023-09-26" @default.
- W2087161907 title "Promoting Vibrations in Human Purine Nucleoside Phosphorylase. A Molecular Dynamics and Hybrid Quantum Mechanical/Molecular Mechanical Study" @default.
- W2087161907 cites W1041023894 @default.
- W2087161907 cites W1568612740 @default.
- W2087161907 cites W1603423304 @default.
- W2087161907 cites W1969423952 @default.
- W2087161907 cites W1970327093 @default.
- W2087161907 cites W1970561265 @default.
- W2087161907 cites W1973700171 @default.
- W2087161907 cites W1976106600 @default.
- W2087161907 cites W1983283509 @default.
- W2087161907 cites W1983559242 @default.
- W2087161907 cites W1993189001 @default.
- W2087161907 cites W2001448561 @default.
- W2087161907 cites W2004303971 @default.
- W2087161907 cites W2006930438 @default.
- W2087161907 cites W2013410957 @default.
- W2087161907 cites W2014829326 @default.
- W2087161907 cites W2020706370 @default.
- W2087161907 cites W2022092718 @default.
- W2087161907 cites W2022671749 @default.
- W2087161907 cites W2027484071 @default.
- W2087161907 cites W2028531632 @default.
- W2087161907 cites W2031860944 @default.
- W2087161907 cites W2041729108 @default.
- W2087161907 cites W2042993993 @default.
- W2087161907 cites W2048984271 @default.
- W2087161907 cites W2064193868 @default.
- W2087161907 cites W2077973224 @default.
- W2087161907 cites W2080770722 @default.
- W2087161907 cites W2084587631 @default.
- W2087161907 cites W2102562821 @default.
- W2087161907 cites W2130752141 @default.
- W2087161907 cites W2162166182 @default.
- W2087161907 doi "https://doi.org/10.1021/ja0457563" @default.
- W2087161907 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/15571394" @default.
- W2087161907 hasPublicationYear "2004" @default.
- W2087161907 type Work @default.
- W2087161907 sameAs 2087161907 @default.
- W2087161907 citedByCount "79" @default.
- W2087161907 countsByYear W20871619072012 @default.
- W2087161907 countsByYear W20871619072013 @default.
- W2087161907 countsByYear W20871619072014 @default.
- W2087161907 countsByYear W20871619072015 @default.
- W2087161907 countsByYear W20871619072016 @default.
- W2087161907 countsByYear W20871619072017 @default.
- W2087161907 countsByYear W20871619072018 @default.
- W2087161907 countsByYear W20871619072019 @default.
- W2087161907 countsByYear W20871619072020 @default.
- W2087161907 countsByYear W20871619072022 @default.
- W2087161907 countsByYear W20871619072023 @default.
- W2087161907 crossrefType "journal-article" @default.
- W2087161907 hasAuthorship W2087161907A5018522950 @default.
- W2087161907 hasAuthorship W2087161907A5019353843 @default.
- W2087161907 hasAuthorship W2087161907A5078283384 @default.
- W2087161907 hasAuthorship W2087161907A5079231031 @default.
- W2087161907 hasConcept C112887158 @default.
- W2087161907 hasConcept C121332964 @default.
- W2087161907 hasConcept C147597530 @default.
- W2087161907 hasConcept C178790620 @default.
- W2087161907 hasConcept C181199279 @default.
- W2087161907 hasConcept C185592680 @default.
- W2087161907 hasConcept C2776476023 @default.
- W2087161907 hasConcept C32909587 @default.
- W2087161907 hasConcept C58364064 @default.
- W2087161907 hasConcept C59593255 @default.
- W2087161907 hasConcept C62520636 @default.
- W2087161907 hasConcept C69928629 @default.
- W2087161907 hasConcept C71240020 @default.
- W2087161907 hasConcept C71615608 @default.
- W2087161907 hasConcept C8010536 @default.
- W2087161907 hasConceptScore W2087161907C112887158 @default.
- W2087161907 hasConceptScore W2087161907C121332964 @default.
- W2087161907 hasConceptScore W2087161907C147597530 @default.
- W2087161907 hasConceptScore W2087161907C178790620 @default.
- W2087161907 hasConceptScore W2087161907C181199279 @default.
- W2087161907 hasConceptScore W2087161907C185592680 @default.
- W2087161907 hasConceptScore W2087161907C2776476023 @default.
- W2087161907 hasConceptScore W2087161907C32909587 @default.
- W2087161907 hasConceptScore W2087161907C58364064 @default.
- W2087161907 hasConceptScore W2087161907C59593255 @default.
- W2087161907 hasConceptScore W2087161907C62520636 @default.
- W2087161907 hasConceptScore W2087161907C69928629 @default.
- W2087161907 hasConceptScore W2087161907C71240020 @default.
- W2087161907 hasConceptScore W2087161907C71615608 @default.
- W2087161907 hasConceptScore W2087161907C8010536 @default.
- W2087161907 hasIssue "48" @default.
- W2087161907 hasLocation W20871619071 @default.
- W2087161907 hasLocation W20871619072 @default.
- W2087161907 hasOpenAccess W2087161907 @default.
- W2087161907 hasPrimaryLocation W20871619071 @default.