HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Bonaventura, J. Articles by Antonini, E. Search for Related Content PubMed PubMed Citation Articles by Bonaventura, J. Articles by Antonini, E. Social Bookmarking                      What's this?

JBC, Vol. 250, Issue 16, 6278-6281, Aug, 1975

Allosteric interactions in non-alpha chains isolated from normal human hemoglobin, fetal hemoglobin, and hemoglobin Abruzzo (beta143 (H21) His replaced by Arg)

J. Bonaventura, C. Bonaventura, G. Amiconi, L. Tentori, M. Brunori and E. Antonini

Oxygen-linked effects of inositol hexaphosphate occur in heme-containing non-alpha chains isolated from normal human hemoglobin, fetal hemoglobin, and the abnormal human hemoglobin Abruzzo, beta143(H21) His leads to Arg. The occurrence of these effects implies that the chains undergo ligand-linked conformational changes. Inositol hexaphosphate lowers the oxygen affinity of isolated beta and gamma chains by differential binding to their deoxy conformations. Neither 2,3-diphosphoglycerate nor inorganic phosphate produces such an effect. In the case of Abruzzo beta chains, the binding of inorganic phosphate and 2,3-diphosphoglycerate is also oxygen-linked. Stripped beta chains isolated from hemoglobin Abruzzo have much higher oxygen affinity than beta chains isolated from HbA. Their higher oxygen affinity and enhanced allosteric interactions with phosphates account, in large part, for the abnormal functional behavior of the hemoglobin Abruzzo tetramer. In this hemoglobin variant the substitution of arginine for histidine at beta143 involves a residue known to interact with anionic allosteric effectors of hemoglobin. It is of interest that the effect of inositol hexaphosphate observed with isolated gamma chains is comparable to the effect observed with isolated beta chains, even though the gamma143 position is occupied by an uncharged serine residue.
CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				Z.-l. Wan, K. Huang, S.-Q. Hu, J. Whittaker, and M. A. Weiss The Structure of a Mutant Insulin Uncouples Receptor Binding from Protein Allostery: AN ELECTROSTATIC BLOCK TO THE TR TRANSITION J. Biol. Chem., July 25, 2008; 283(30): 21198 - 21210. [Abstract] [Full Text] [PDF]