Accession Number : ADA306017

Title :   Carboxyalkylated Crosslinked Hemoglobin as a Potential Blood Substitute.

Descriptive Note : Final rept. 15 Jun 94-31 Jan 96,

Corporate Author : ROCKEFELLER UNIV NEW YORK

Personal Author(s) : Manning, James M.

PDF Url : ADA306017

Report Date : MAR 1996

Pagination or Media Count : 27

Abstract : Prior to preparing 128,000 cross-linked Hb, a method was devised to study subunit dissociation. A precise and rapid procedure employing gel filtration on Superose-12 to measure the tetramer-dimer dissociation constants of some natural and recombinant hemoglobins in the oxy conformation is described. Natural sickle hemoglobin was chosen to verify the validity of the results by comparing the values with those reported using an independent method not based on gel filtration. Recombinant sickle hemoglobin, as well as a sickle double mutant with a substitution at the Val-6(Beta) receptor site, had approximately the same dissociation constant as natural sickle hemoglobin. Of the two recombinant hemoglobins with amino acid replacements in the alpha(1)Beta(2) subunit interface, one was found to be extensively dissociated and the other completely dissociated. In addition, the absence of an effect of the allosteric regulators DPG and IHP on the dissociation constant was demonstrated. Thus, a tetramer dissociation constant can now be readily determined and used together with other criteria for characterization of hemoglobins and their interaction with small regulatory molecules.

Descriptors :   *HEMOGLOBIN, *DISSOCIATION, *BLOOD SUBSTITUTES, VALIDATION, MUTATIONS, CROSSLINKING(CHEMISTRY), PRECISION, REPLACEMENT, GELS, AMINO ACIDS, FILTRATION, SICKLE CELLS.

Subject Categories : Anatomy and Physiology
      Biochemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE