Rh polypeptide is a major fatty acid-acylated erythrocyte membrane protein
The erythrocyte Rh antigens contain an Mr = 32,000 integral protein which is thought to contribute in some way to the organization of surrounding phospholipid. To search for possible fatty acid acylation of the Rh polypeptide, intact human erythrocytes were incubated with (3H)palmitic acid prior to preparation of membranes and sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorography. Several membrane proteins were labeled, but none corresponded to the glycophorins or membrane proteins 1-8. An Mr = 32,000 band was prominently labeled on Rh (D)-negative and -positive erythrocytes and could be precipitated from the latter with anti-D. No similar protein was labeled on membranes from Rhmod erythrocytes, a rare phenotype lacking Rh antigens. Labeling of the Rh polypeptide most likely represents palmitic acid acylation through thioester linkages. The 3H label was not extracted with chloroform/methanol, but was quantitatively eluted with hydroxylamine and co-chromatographed with palmitohydroxamate and free palmitate by thin layer chromatography. The fatty acid acylations occurred independent of protein synthesis and were completely reversed by chase with unlabeled palmitate. It is concluded that the Rh polypeptide is fatty acid-acylated, being a major substrate of an acylation-deacylation mechanism associated with the erythrocyte membrane.
- Research Organization:
- Johns Hopkins Univ. School of Medicine, Baltimore, MD (USA)
- OSTI ID:
- 6611717
- Journal Information:
- J. Biol. Chem.; (United States), Vol. 263:34
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
HEXADECANOIC ACID
ACYLATION
POLYPEPTIDES
LABELLING
BLOOD GROUPS
CELL MEMBRANES
ELECTROPHORESIS
ERYTHROCYTES
MAN
MEMBRANE PROTEINS
THIN-LAYER CHROMATOGRAPHY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
ANIMALS
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CARBOXYLIC ACIDS
CELL CONSTITUENTS
CHEMICAL REACTIONS
CHROMATOGRAPHY
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MEMBRANES
MONOCARBOXYLIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
PEPTIDES
PRIMATES
PROTEINS
SEPARATION PROCESSES
VERTEBRATES
550201* - Biochemistry- Tracer Techniques