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Labelling of the intramembranous region of the major sialoglycoprotein of human erythrocytes with a photosensitive hydrophobic probe.

ABSTRACT: Human erythrocyte membranes were incubated with the photosensitive hydrophobic reagent 1-azido-r-iodo[3H]benzene and the mixture was irradiated. The major sialoglycoprotein was then isolated and the labelled polypeptide subjected to proteolytic dissection. Characterization of the purified tryptic and chymotryptic peptides show that the probe is covalently attached only to the transmembrane region of the protein. This labelling pattern is discussed in relation to the use of such reagents for the identification of segments of membrane proteins exposed to the hydrophobic millieu of the membrane.

SUBMITTER: Wells E

PROVIDER: S-EPMC1186623 | biostudies-other | 1979 May

REPOSITORIES: biostudies-other

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The isolation of human-erythrocyte band-3 polypeptide labelled with a photosensitive hydrophobic probe.

Project description:To investigate the intramembranous domains of the major band-3 polypeptide, human erythrocyte membranes were labelled with 1-azido-4-[125I]iodobenzene. The anion-exchange protein has been isolated by a new procedure that decreases possible contamination by other integral membrane proteins of similar molecular weight. After chemical modification, the protein was subjected to proteolytic cleavage by several proteinases to yield a distinct pattern of peptides, a few of which contained radioactivity.

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Use of photosensitive hydrophobic probes to label the membrane of the human erythrocyte.

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