当前位置： SCI文献检索 > BIOCHEMISTRY期刊下所有文献 > Cytochrome c peroxidase mutant active site structures probed by resonance Raman and infrared signatures of the CO adducts.

Cytochrome c peroxidase mutant active site structures probed by resonance Raman and infrared signatures of the CO adducts.

Abstract：

:Vibrational frequencies associated with FeC and CO stretching and FeCO bending modes have been determined via resonance Raman (RR) and infrared (IR) spectroscopy for cytochrome c peroxidase (CCP) mutants prepared by site-directed mutagenesis. These include the bacterial "wild type", CCP(MI), and mutations involving groups on the proximal (Asp-235----Asn; Trp-191---Phe) and distal (Trp-51----Phe; Arg-48----Leu and Lys) side of the heme. The data were analyzed with the aid of a recently established correlation between nu FeC and nu CO, which can be used to distinguish between back-bonding and axial ligand donor effects. At high pH all adducts showed essentially the same vibrational pattern (form I') with nu FeC approximately 505 cm-1, nu CO approximately 1948 cm-1, and delta FeCO (weak RR band) approximately 576 cm-1. These frequencies are very similar to those shown by the myoglobin CO adduct and imply a "normal" H-bond of the proximal histidine. At pH 7 (pH 6 for Asn-235 and Leu-48), different forms are seen for different proteins: form I (nu FeC approximately 500 cm-1, nu CO = 1922-1941 cm-1, and delta FeCO approximately 580 cm-1, very weak) in the case of CCP(MI) and Phe-191, as well as bakers' yeast CCP, or form II (nu FeC approximately 530 cm-1, nu CO = 1922-1933 cm-1, and delta FeCO = 585 cm-1, moderately strong) for Asn-235 and Phe-51.(ABSTRACT TRUNCATED AT 250 WORDS)

journal_name

Biochemistry

journal_title

Biochemistry

authors

Smulevich G,Mauro JM,Fishel LA,English AM,Kraut J,Spiro TG

doi

10.1021/bi00415a015

subject

Has Abstract

pub_date

1988-07-26 00:00:00

pages

5486-92

issue

15

eissn

0006-2960

issn

1520-4995

journal_volume

27

pub_type

杂志文章

相关文献

BIOCHEMISTRY文献大全