Matches in SemOpenAlex for { <https://semopenalex.org/work/W2023104995> ?p ?o ?g. }
- W2023104995 endingPage "227" @default.
- W2023104995 startingPage "214" @default.
- W2023104995 abstract "We have measured the VFe-His Raman band of horse heart deoxymyoglobin dissolved in an aqueous solution as a function of temperature between 10 and 300 K. The minimal model to which these data can be fitted in a statistically significant and physically meaningful way comprises four different Lorentzian bands with frequencies at 197, 209, 218, and 226 cm-1, and a Gaussian band at 240 cm-1, which exhibit halfwidths between 10 and 12.5 cm-1. All these parameters were assumed to be independent of temperature. The temperature dependence of the apparent total band shape's frequency is attributed to an intensity redistribution of the subbands at omega 1 = 209 cm-1, omega 2 = 218 cm-1, and omega 3 = 226 cm-1, which are assigned to Fe-N epsilon (HisF8) stretching modes in different conformational substrates of the Fe-HisF8 linkage. They comprise different out-of-plane displacements of the heme iron. The two remaining bands at 197 and 240 cm-1 result from porphyrin modes. Their intensity ratio is nearly temperature independent. The intensity ratio I3/I2 of the vFe-His subbands exhibits a van't Hoff behavior between 150 and 300 K, bending over in a region between 150 and 80 K, and remains constant between 80 and 10 K, whereas I2/I1 shows a maximum at 170 K and approaches a constant value at 80 K. These data can be fitted by a modified van't Hoff expression, which accounts for the freezing into a non-equilibrium distribution of substates below a distinct temperature Tf and also for the linear temperature dependence of the specific heat of proteins. The latter leads to a temperature dependence of the entropic and enthalpic differences between conformational substates. The fits to the intensity ratios of the vFe-His subbands yield a freezing temperature of Tf = 117 K and a transition region of delta T = 55 K. In comparison we have utilized the above thermodynamic model to reanalyze earlier data on the temperature dependence of the ratio Ao/A1 of two subbands underlying the infrared absorption band of the CO stretching vibration in CO-ligated myoglobin (A. Ansari, J. Berendzen, D. Braunstein, B. R. Cowen, H. Frauenfelder, M. K. Kong, I. E. T. Iben, J. Johnson, P. Ormos, T. B. Sauke, R. Scholl, A. Schulte, P. J. Steinbach, R. D. Vittitow, and R. D. Young, 1987, Biophys. Chem. 26:237-335). This yields thermodynamic parameters, in particular the freezing temperature (Tf = 231 K) and the width of the transition region (AT =8 K), which are significantly different from the corresponding parameters obtained from the above vFe-His data, but very close to values describing the transition of protein bound water from a liquid into an amorphous state. These findings and earlier reported data on the temperature dependence exhibited by the Soret absorption bands of various deoxy and carbonmonoxymyoglobins led us to the conclusion that the fluctuations between conformational substates of the heme environment in carbonmonoxymyoglobin are strongly coupled to motions within the hydration shell, whereas the thermal motions between the substates of the Fe-HisF8 linkage in deoxymyoglobin proceed on an energy landscape that is mainly determined by the intrinsic properties of the protein. The latter differ from protein fluctuations monitored by Mossbauer experiments ondeoxymyoglobin crystals which exhibit a strong coupling to the protein bound water and most probably reflect a higher tier in the hierarchical arrangement of substates and equilibrium fluctuations." @default.
- W2023104995 created "2016-06-24" @default.
- W2023104995 creator A5001053464 @default.
- W2023104995 creator A5030213258 @default.
- W2023104995 creator A5071942997 @default.
- W2023104995 date "1995-07-01" @default.
- W2023104995 modified "2023-09-28" @default.
- W2023104995 title "Thermal fluctuations between conformational substates of the Fe(2+)-HisF8 linkage in deoxymyoglobin probed by the Raman active Fe-N epsilon (HisF8) stretching vibration" @default.
- W2023104995 cites W1241480207 @default.
- W2023104995 cites W1430893128 @default.
- W2023104995 cites W1483519460 @default.
- W2023104995 cites W1523477175 @default.
- W2023104995 cites W159197400 @default.
- W2023104995 cites W1966211961 @default.
- W2023104995 cites W1966312962 @default.
- W2023104995 cites W1967733696 @default.
- W2023104995 cites W1968607633 @default.
- W2023104995 cites W1971472724 @default.
- W2023104995 cites W1972574238 @default.
- W2023104995 cites W1976646694 @default.
- W2023104995 cites W1978862989 @default.
- W2023104995 cites W1983565918 @default.
- W2023104995 cites W1984637403 @default.
- W2023104995 cites W1984965754 @default.
- W2023104995 cites W1987049517 @default.
- W2023104995 cites W1993817353 @default.
- W2023104995 cites W1997419902 @default.
- W2023104995 cites W1999136578 @default.
- W2023104995 cites W2000212161 @default.
- W2023104995 cites W2000770794 @default.
- W2023104995 cites W2001931346 @default.
- W2023104995 cites W2003361290 @default.
- W2023104995 cites W2008407134 @default.
- W2023104995 cites W2009553111 @default.
- W2023104995 cites W2017644006 @default.
- W2023104995 cites W2017981842 @default.
- W2023104995 cites W2021664957 @default.
- W2023104995 cites W2023492753 @default.
- W2023104995 cites W2030568700 @default.
- W2023104995 cites W2038068557 @default.
- W2023104995 cites W2039963111 @default.
- W2023104995 cites W2040355223 @default.
- W2023104995 cites W2045159840 @default.
- W2023104995 cites W2049758579 @default.
- W2023104995 cites W2051326312 @default.
- W2023104995 cites W2055777388 @default.
- W2023104995 cites W2058396634 @default.
- W2023104995 cites W2058732262 @default.
- W2023104995 cites W2066289982 @default.
- W2023104995 cites W2067524847 @default.
- W2023104995 cites W2072463712 @default.
- W2023104995 cites W2075092972 @default.
- W2023104995 cites W2078093171 @default.
- W2023104995 cites W2082253404 @default.
- W2023104995 cites W2082353137 @default.
- W2023104995 cites W2087075174 @default.
- W2023104995 cites W2094800878 @default.
- W2023104995 cites W2114615491 @default.
- W2023104995 cites W2161257885 @default.
- W2023104995 doi "https://doi.org/10.1016/s0006-3495(95)79893-9" @default.
- W2023104995 hasPubMedCentralId "https://www.ncbi.nlm.nih.gov/pmc/articles/1236239" @default.
- W2023104995 hasPubMedId "https://pubmed.ncbi.nlm.nih.gov/7669899" @default.
- W2023104995 hasPublicationYear "1995" @default.
- W2023104995 type Work @default.
- W2023104995 sameAs 2023104995 @default.
- W2023104995 citedByCount "21" @default.
- W2023104995 countsByYear W20231049952012 @default.
- W2023104995 crossrefType "journal-article" @default.
- W2023104995 hasAuthorship W2023104995A5001053464 @default.
- W2023104995 hasAuthorship W2023104995A5030213258 @default.
- W2023104995 hasAuthorship W2023104995A5071942997 @default.
- W2023104995 hasBestOaLocation W20231049951 @default.
- W2023104995 hasConcept C113196181 @default.
- W2023104995 hasConcept C120665830 @default.
- W2023104995 hasConcept C121332964 @default.
- W2023104995 hasConcept C185592680 @default.
- W2023104995 hasConcept C2779557605 @default.
- W2023104995 hasConcept C40003534 @default.
- W2023104995 hasConcept C43617362 @default.
- W2023104995 hasConcept C46141821 @default.
- W2023104995 hasConcept C62520636 @default.
- W2023104995 hasConcept C8010536 @default.
- W2023104995 hasConcept C93038891 @default.
- W2023104995 hasConceptScore W2023104995C113196181 @default.
- W2023104995 hasConceptScore W2023104995C120665830 @default.
- W2023104995 hasConceptScore W2023104995C121332964 @default.
- W2023104995 hasConceptScore W2023104995C185592680 @default.
- W2023104995 hasConceptScore W2023104995C2779557605 @default.
- W2023104995 hasConceptScore W2023104995C40003534 @default.
- W2023104995 hasConceptScore W2023104995C43617362 @default.
- W2023104995 hasConceptScore W2023104995C46141821 @default.
- W2023104995 hasConceptScore W2023104995C62520636 @default.
- W2023104995 hasConceptScore W2023104995C8010536 @default.
- W2023104995 hasConceptScore W2023104995C93038891 @default.
- W2023104995 hasIssue "1" @default.
- W2023104995 hasLocation W20231049951 @default.
- W2023104995 hasLocation W20231049952 @default.
- W2023104995 hasLocation W20231049953 @default.