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: Target molecular weights for red cell band 3 stilbene and mercurial binding sites.
    Author: Verkman AS, Skorecki KL, Jung CY, Ausiello DA.
    Journal: Am J Physiol; 1986 Oct; 251(4 Pt 1):C541-8. PubMed ID: 3020989.
    Abstract:
    Radiation inactivation was used to measure the target sizes for binding of disulfonic stilbene anion transport inhibitor 4,4'-dibenzamido-2,2'-disulfonic stilbene (DBDS) and mercurial water transport inhibitor p-chloromercuribenzene sulfonate (pCMBS) to human erythrocytes. The measured target size for erythrocyte ghost acetylcholinesterase was 78 +/- 3 kDa. DBDS binding to ghost membranes was measured by a fluorescence enhancement technique. Radiation (0-26 Mrad) had no effect on total membrane protein and DBDS binding affinity, whereas DBDS binding stoichiometry decreased exponentially with radiation dose, giving a target size of 59 +/- 4 kDa. H2-4,4'-diisothiocyano-2,2'-disulfonic stilbene (H2-DIDS, 5 microM) blocked greater than 95% of DBDS binding at all radiation doses. pCMBS binding was measured from the time course of tryptophan fluorescence quenching in ghosts treated with the sulfhydryl reagent N-ethylmaleimide (NEM). Radiation did not affect the kinetics of tryptophan quenching, whereas the total amplitude of the fluorescence signal inactivated with radiation with a target size of 31 +/- 6 kDa. These results support the notion that DBDS and pCMBS bind to the transmembrane domain of erythrocyte band 3 in NEM-treated ghosts and demonstrate that radiation inactivation may probe a target significantly smaller than a covalently linked protein subunit. The small target size for the band 3 stilbene binding site may correspond to the intramembrane domain of the band 3 monomer (52 kDa), which is physically distinct from the cytoplasmic domain (42 kDa).
    [Abstract] [Full Text] [Related] [New Search]