Aminophospholipid translocation in erythrocytes: Evidence for the involvement of a specific transporter and an endofacial protein

Journal Article · Tue Jan 09 04:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00453a005· OSTI ID:7118523

Connor, J; Schroit, A J ^[1]

---

1. Univ. of Texas M.D. Anderson Cancer Center, Houston (USA)

The transport of exogenously supplied fluorescent analogues of aminophospholipids from the outer to inner leaflet in red blood cells (RBC) is dependent upon the oxidative status of membrane sulfhydryls. Oxidation of a sulfhydryl on a 32-kDa membrane protein by pyridyldithioethylamine (PDA) has been previously shown to inhibit the transport of NBD-labeled phosphatidylserine (NBD-PS). In the present study, other sulfhydryl oxidants were examined to determine whether additional sites are involved in the transport process. The results show that diamide inhibits the transport of NBD-PS via a mechanism that is independent of the 32-kDa site. This is shown by the inability of diamide to block labeling of the 32-kDa sulfhydryl with {sup 125}I-labeled PDA and to protect against PDA-mediated inhibition of NBD-PS transport. Diamide-mediated inhibition, but not PDA-mediated inhibition, could be reversed by reduction with cysteamine or endogenous glutathione. Once established, the asymmetric distribution of NBD-PS could not be altered by oxidation of either site. These data indicate that a second site critical to the transport of aminophospholipids residues on the endofacial surface and suggest that the transport of aminophospholipids across the bilayer membrane of RBC depends on a coordinated and complementary process between a cytoskeletal component and the 32-kDa membrane polypeptide; both must be operative for transport to proceed.

• OSTI ID: 7118523
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:1; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BIOCHEMISTRY
BIOLOGICAL MATERIALS
BLOOD
BLOOD CELLS
BODY FLUIDS
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
CHEMISTRY
CROSS-LINKING
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ERYTHROCYTES
ESTERS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
KINETICS
LIPIDS
MATERIALS
MEMBRANE PROTEINS
MEMBRANE TRANSPORT
MEMBRANES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PHOSPHOLIPIDS
POLYMERIZATION
PROTEINS
RADIOISOTOPES
REACTION KINETICS
THIOLS