Linked Life Data

3442657

Source:http://linkedlifedata.com/resource/pubmed/id/3442657

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
25
pubmed:dateCreated
1988-5-3
pubmed:abstractText
Resonance Raman (RR) spectra are reported for the deoxy, oxy, and metcyano species of sperm whale myoglobin (Mb) reconstituted with deuteroheme, 2-acetyldeuteroheme, 4-acetyldeuteroheme, and 2,4-diacetyldeuteroheme. The functional inequivalence of the 2- and 4-positions of the heme moiety is manifested in the vibrational frequencies of the carbonyl and certain heme skeletal modes. The RR data indicate that the protein influences the porphyrin pi-system primarily through the 2-substituent. In the deoxy Mbs, the 2-acetyl group is more conjugated into the pi-macrocycle than the 4-acetyl group. In the ligated Mbs, the extent of conjugation of the 2-group is less than in the deoxy forms. This result indicates that ligand binding differentially alters the pi-electronic structure for 2- vs 4-substituted systems. The proximal histidine-iron stretching vibration of all four deoxy Mbs occurs at 222 +/- 1 cm-1, which indicates that the substituent-induced changes in the pi-electronic structure do not result in large changes of the electron density in the axial ligand bonds. RR spectra recorded immediately after heme reconstitution indicate the presence of two inequivalent forms of the protein. 1H NMR spectroscopy indicates that these two forms are the normal and reversed heme orientational isomers previously described by La Mar and co-workers [La Mar, G.N., Budd, D.L., Viscio, D.B., Smith, K.M., & Langry, K.C. (1978) Proc. Natl. Acad. Sci. U.S.A. 75, 5755-5759]. The RR spectra demonstrate that in the deoxy species the 2-acetyl group of the normal form is conjugated into the macrocycle to approximately the same extent as the 4-acetyl group of the reversed form and vice versa.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8319-26
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Resonance Raman studies of acetylheme-reconstituted myoglobins. Characterization of 2- versus 4-substituent/protein interactions.
pubmed:affiliation
Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.