These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Subunit interactions of Glycera dibranchiata hemoglobin.
    Author: Harrington JP, Suarez G, Borgese TA, Nagel RL.
    Journal: J Biol Chem; 1978 Oct 10; 253(19):6820-5. PubMed ID: 29042.
    Abstract:
    The coelomic cells of the polychaete annelid Glycera dibranchiata contain two hemoglobins. The monomer hemoglobin fraction is composed of one major component and two minor components as determined by starch gel electrophoresis and isoelectrofocusing, but is homogeneous as to subunit size as demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The polymer hemoglobin fraction has and initial molecular weight of Mn = 125,000 as determined by osmometry, but exhibits an increased state of aggregation upon storage. The quaternary structure of the polymer is constituted of monomeric subunits in a non-covalent state of aggregation as demonstrated by its subunit dissociation inthe presence of propyl urea. The oxygen affinity of the polymer is lower than the monomer but increases with deaggregation. The Bohr effect is present only in the polymer. Cooperativity is also characteristic of the polymer and is pH-dependent. Interestingly, cooperativity increases with intermediate states of polymer deaggregation. By far, the main organic phosphate component of the coelomic red cells is ATP accompanied by small amounts of ADP and GTP. No modulating effect of ATP on the oxygen equilibrium of either polymer or total hemolysate was found.
    [Abstract] [Full Text] [Related] [New Search]