Mutational study of the bacterial hemoglobin distal heme pocket.

Verma, Sandhya and Patel, Sangeeta and Kaur, Ramandeep and Chung, Yeon-Tae and Duk, Brian T and Dikshit, Kanak L and Stark, Benjamin C and Webster, Dale A (2005) Mutational study of the bacterial hemoglobin distal heme pocket. Biochemical and biophysical research communications, 326 (2). pp. 290-7. ISSN 0006-291X

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Abstract

Ligand binding experiments on three mutants in the distal heme pocket of Vitreoscilla hemoglobin (GlnE7His, ProE8Ala, and GlnE7His,ProE8Ala) were used to probe the role of GlnE7 and ProE8 in the pocket's unusual structure. The oxygen dissociation constants for the wild type, E8Ala mutant, and E7His mutant proteins were 4.5, 4.7, and 1.7microM, respectively; the K(d) for the double mutant was not determinable by our technique. Visible-Soret spectra of the carbonyl and cyanyl forms and FT-IR of the carbonyl form of the E8 mutant were similar to those of the wild type; the opposite was true for the GlnE7His and GlnE7His,ProE8Ala mutants, which also differed from wild type in the visible-Soret spectra of their oxidized forms. Models of the effects of the mutations on distal pocket structure were consistent with the experimental findings, particularly the larger effects of the GlnE7His change.

Item Type:	Article
Additional Information:	Copyright of this article belongs to Elsevier Science.
Uncontrolled Keywords:	Carbon monoxide; Cyanide; Heme pocket; Mutant hemoglobins; Oxygen; Vitreoscilla hemoglobin
Subjects:	Q Science > QD Chemistry
Depositing User:	Dr. K.P.S.Sengar
Date Deposited:	15 Feb 2012 14:36
Last Modified:	15 Feb 2012 14:36
URI:	http://crdd.osdd.net/open/id/eprint/1001

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