Linked Life Data

3179264

Source:http://linkedlifedata.com/resource/pubmed/id/3179264

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1988-12-22
pubmed:abstractText
Ultraviolet resonance Raman spectra with 229-nm excitation are reported for aqueous tyrosine and for ovomucoid third domain proteins from chicken [OMCHI3(-)] and from chachalaca [OMCHA(-)], as well as alpha 1-, alpha 2-, and beta-purothionin. At this excitation wavelength interference from phenylalanine is minimized, and it is possible to determine the frequencies of the Tyr ring modes nu 8a and nu 8b. The nu 8b frequency decreases with the degree of Tyr H-bond donation, reaching a limiting value for deprotonated tyrosine. This spectroscopic indicator of H-bond strength was calibrated by using the model compound p-cresol in H-bond acceptor solutions for which the enthalpy of H-bond formation can be obtained from the literature. With this calibration it is possible to estimate Tyr H-bond enthalpies in proteins for which Tyr is a H-bond donor; values of 13.7, 9.6, and 11.2 kcal/mol were found for OMCHA3(-) and for alpha 1- (or alpha 2-) and beta-purothionin, respectively. The intensity of the 1176-cm-1 nu 9a band of Tyr excited at 229 nm and also the intensity ratio of the Tyr 830/850-cm-1 Fermi doublet excited at 200 nm both correlate strongly with the estimated H-bond enthalpies, but large deviations are seen for the purothionins, reflecting a special environment for the Tyr residue of these proteins, which is believed to be constrained in a hydrophobic pocket. The molar intensity of the strong approximately 1000-cm-1 nu 12 band of phenylalanine in aqueous solution is about half the value observed in most proteins.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5426-33
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Tyrosine hydrogen-bonding and environmental effects in proteins probed by ultraviolet resonance Raman spectroscopy.
pubmed:affiliation
Department of Chemistry, Princeton University, New Jersey 08544.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.