Structure of the anion-transport protein of the human erythrocyte membrane. Further studies on the fragments produced by proteolytic digestion

Publisher Website
Google Scholar
Abstract
Topology of the human erythrocyte membrane anion-transport protein (band 3) was investigated by isolation and peptide mapping of major and minor fragments derived from proteolytic cleavage of the lactoperoxidase 125I-labeled protein in erythrocytes and erythrocyte membranes. In each fragment, content of lactoperoxidase 125I-labeled sites (which have a known location in the extracellular or cytoplasmic protein domain), together with location of the sites of proteolytic cleavage yielding the fragments, allowed fragment alignment on the linear amino acid sequence to be determined and topology of the polypeptide in the membrane to be inferred. A region in the C-terminal portion of the polypeptide apparently forms part of the cytoplasmic protein domain in addition to a large N-terminal segment. Membrane-bound protein regions are located in the C-terminal 2/3 of the molecule. In this region in the polypeptide chain traverses the membrane at least 4 times, and an additional polypeptide loop is embedded in the membrane or also penetrates through it to the other surface. Location of lectin receptors on the protein and the binding site of an anion-transport inhibitor were also studied.

This publication has 33 references indexed in Scilit: