Matches in SemOpenAlex for { <https://semopenalex.org/work/W1489727944> ?p ?o ?g. }
Showing items 1 to 100 of
100
with 100 items per page.
- W1489727944 endingPage "598" @default.
- W1489727944 startingPage "591" @default.
- W1489727944 abstract "When a protein's active site happens to be strongly coupled with the protein structure, the rate constant of the reaction may eventually be modulated by the conformational fluctuations. Evidence for this effect has long been provided by extensive flash photolysis investigations of liganded hemoproteins and more recently of the non-heme respiratory protein hemerythrin in hydro-organic solvents. Within a given protein conformational substate, an elementary reaction step is characterized by one single free energy barrier and by a first-order rate constant, k, which changes with temperature according to an Arrhenius law. At physiological temperature and low viscosity, ultrafast conformational relaxation causes efficient averaging of the reaction rates and the protein displays exponential kinetics with an average rate constant (k). Under sufficiently general conditions, it can be shown that (k) also follows a simple Arrhenius law with 'effective' values of the pre-exponential factor Aeff and activation enthalpy Heff. It is found that Aeff strongly depends on the overall shape of the rate constant distribution and that Heff actually corresponds to the lower limit of the enthalpy of activation, i.e. the value associated with the highest possible reaction rate. The underlying distribution of rate constants can be reconstructed from a set of experiments in which the kinetics depart from an exponential, i.e. at low temperature and high viscosity. The most probable distribution of exponentials consistent with the observed kinetics of the geminate recombinations of oxygen with photodissociated hemerythrin has been determined by using a new approach, known as the maximum entropy method. The results are consistent with a single pre-exponential value and a distributed enthalpy spectrum. As expected, Heff does not coincide either with the most probable nor with the average value of the enthalpy. The most salient findings are that the probability for any protein molecule to have an enthalpy of activation equal to the effective value Heff vanishes and that Aeff differs by nearly three orders of magnitude from the true value A0. Biochemical reaction rates are actually average values, since protein reactions are measured under physiological conditions, where conformational relaxation is always fast. Our understanding of the significance of Aeff and Heff is therefore entirely dependent on the knowledge of the distribution function of the rate constants. In particular, enthalpy and entropy terms of similar reactions performed by different proteins cannot be compared as long as the distribution of the rate constants remains unknown." @default.
- W1489727944 created "2016-06-24" @default.
- W1489727944 creator A5004688026 @default.
- W1489727944 creator A5030778270 @default.
- W1489727944 creator A5063285004 @default.
- W1489727944 creator A5085099000 @default.
- W1489727944 date "1991-03-01" @default.
- W1489727944 modified "2023-09-23" @default.
- W1489727944 title "Conformational fluctuations and protein reactivity. Determination of the rate-constant spectrum and consequences in elementary biochemical processes" @default.
- W1489727944 cites W1974396570 @default.
- W1489727944 cites W1979546591 @default.
- W1489727944 cites W1982589567 @default.
- W1489727944 cites W1983738982 @default.
- W1489727944 cites W1993187009 @default.
- W1489727944 cites W1999136578 @default.
- W1489727944 cites W2003641880 @default.
- W1489727944 cites W2021664957 @default.
- W1489727944 cites W2040355223 @default.
- W1489727944 cites W2056069383 @default.
- W1489727944 cites W2078451235 @default.
- W1489727944 cites W2078861992 @default.
- W1489727944 cites W2090159140 @default.
- W1489727944 cites W2094164772 @default.
- W1489727944 cites W2094484408 @default.
- W1489727944 cites W2951339792 @default.
- W1489727944 cites W3185172400 @default.
- W1489727944 doi "https://doi.org/10.1111/j.1432-1033.1991.tb15854.x" @default.
- W1489727944 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/2013282" @default.
- W1489727944 hasPublicationYear "1991" @default.
- W1489727944 type Work @default.
- W1489727944 sameAs 1489727944 @default.
- W1489727944 citedByCount "31" @default.
- W1489727944 countsByYear W14897279442012 @default.
- W1489727944 countsByYear W14897279442017 @default.
- W1489727944 crossrefType "journal-article" @default.
- W1489727944 hasAuthorship W1489727944A5004688026 @default.
- W1489727944 hasAuthorship W1489727944A5030778270 @default.
- W1489727944 hasAuthorship W1489727944A5063285004 @default.
- W1489727944 hasAuthorship W1489727944A5085099000 @default.
- W1489727944 hasBestOaLocation W14897279441 @default.
- W1489727944 hasConcept C121332964 @default.
- W1489727944 hasConcept C13472781 @default.
- W1489727944 hasConcept C147597530 @default.
- W1489727944 hasConcept C147789679 @default.
- W1489727944 hasConcept C148898269 @default.
- W1489727944 hasConcept C15744967 @default.
- W1489727944 hasConcept C161790260 @default.
- W1489727944 hasConcept C175113610 @default.
- W1489727944 hasConcept C178790620 @default.
- W1489727944 hasConcept C180188523 @default.
- W1489727944 hasConcept C185592680 @default.
- W1489727944 hasConcept C2776029896 @default.
- W1489727944 hasConcept C3288061 @default.
- W1489727944 hasConcept C62520636 @default.
- W1489727944 hasConcept C77805123 @default.
- W1489727944 hasConcept C86183883 @default.
- W1489727944 hasConcept C93391505 @default.
- W1489727944 hasConcept C95121573 @default.
- W1489727944 hasConcept C97355855 @default.
- W1489727944 hasConceptScore W1489727944C121332964 @default.
- W1489727944 hasConceptScore W1489727944C13472781 @default.
- W1489727944 hasConceptScore W1489727944C147597530 @default.
- W1489727944 hasConceptScore W1489727944C147789679 @default.
- W1489727944 hasConceptScore W1489727944C148898269 @default.
- W1489727944 hasConceptScore W1489727944C15744967 @default.
- W1489727944 hasConceptScore W1489727944C161790260 @default.
- W1489727944 hasConceptScore W1489727944C175113610 @default.
- W1489727944 hasConceptScore W1489727944C178790620 @default.
- W1489727944 hasConceptScore W1489727944C180188523 @default.
- W1489727944 hasConceptScore W1489727944C185592680 @default.
- W1489727944 hasConceptScore W1489727944C2776029896 @default.
- W1489727944 hasConceptScore W1489727944C3288061 @default.
- W1489727944 hasConceptScore W1489727944C62520636 @default.
- W1489727944 hasConceptScore W1489727944C77805123 @default.
- W1489727944 hasConceptScore W1489727944C86183883 @default.
- W1489727944 hasConceptScore W1489727944C93391505 @default.
- W1489727944 hasConceptScore W1489727944C95121573 @default.
- W1489727944 hasConceptScore W1489727944C97355855 @default.
- W1489727944 hasIssue "3" @default.
- W1489727944 hasLocation W14897279441 @default.
- W1489727944 hasLocation W14897279442 @default.
- W1489727944 hasOpenAccess W1489727944 @default.
- W1489727944 hasPrimaryLocation W14897279441 @default.
- W1489727944 hasRelatedWork W1670603353 @default.
- W1489727944 hasRelatedWork W1965045873 @default.
- W1489727944 hasRelatedWork W1988649933 @default.
- W1489727944 hasRelatedWork W1999977692 @default.
- W1489727944 hasRelatedWork W2007384977 @default.
- W1489727944 hasRelatedWork W2022464089 @default.
- W1489727944 hasRelatedWork W2042236262 @default.
- W1489727944 hasRelatedWork W3109188768 @default.
- W1489727944 hasRelatedWork W3145274971 @default.
- W1489727944 hasRelatedWork W818543870 @default.
- W1489727944 hasVolume "196" @default.
- W1489727944 isParatext "false" @default.
- W1489727944 isRetracted "false" @default.
- W1489727944 magId "1489727944" @default.
- W1489727944 workType "article" @default.