Identification of the sodium-calcium exchanger as the major ricin-binding glycoprotein of bovine rod outer segments and its localization to the plasma membrane

Journal Article · Mon Feb 12 23:00:00 EST 1990 · Biochemistry; (USA)

DOI:https://doi.org/10.1021/bi00458a035· OSTI ID:6940822

Reid, D M; Molday, R S ^[1]; Friedel, U; Cook, N J ^[2]

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1. Univ. of British Columbia, Vancouver (Canada)
2. Max-Planck Institut fur Biophysik, Frankfurt (West Germany)

After neuraminidase treatment the Na{sup +}/Ca{sup 2+} exchanger of bovine rod outer segments was found to specifically bind Ricinus communis agglutinin. SDS gel electrophoresis and Western blotting of ricin-binding proteins purified from rod outer segment membranes by lectin affinity chromatography revealed the existence of two major polypeptides of M{sub r} 215K and 103K, the former of which was found to specifically react with PMe 1B3, a monoclonal antibody specific for the 230-kDa non-neuraminidase-treated Na{sup +}/Ca{sup 2+} exchanger. Reconstitution of the ricin affinity-purified exchanger into calcium-containing liposomes revealed that neuraminidase treatment had no significant effect on the kinetics of Na{sup +}/Ca{sup 2+} exchange activation by sodium. The authors further investigated the density of the Na{sup +}/Ca{sup 2+} exchanger in disk and plasma membrane preparations using Western blotting, radioimmunoassays, immunoelectron microscopy, and reconstitution procedures. The results indicate that the Na{sup +}/Ca{sup 2+} exchanger is localized in the rod photoreceptor plasma membrane and is absent or present in extremely low concentrations in disk membranes, as they have previously shown to be the case for the cGMP-gated cation channel. Previous reports describing the existence of Na{sup +}/Ca{sup 2+} exchange activity in rod outer segment disk membrane preparations may be due to the fusion of plasma membrane components and/or the presence of contaminating plasma membrane vesicles.

• OSTI ID: 6940822
• Journal Information: Biochemistry; (USA), Journal Name: Biochemistry; (USA) Vol. 29:6; ISSN 0006-2960; ISSN BICHA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALI METAL COMPOUNDS
ALKALINE EARTH METAL COMPOUNDS
ANIMALS
BETA DECAY RADIOISOTOPES
BIOASSAY
BODY
BODY AREAS
CALCIUM COMPOUNDS
CATTLE
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
DIAGNOSTIC TECHNIQUES
DISTRIBUTION
DOMESTIC ANIMALS
ELECTRON CAPTURE RADIOISOTOPES
ELECTRON MICROSCOPY
ELECTROPHORESIS
ENZYMES
EYES
FACE
GLYCOPROTEINS
HEAD
HYDROLASES
IMMUNOASSAY
IMMUNOLOGY
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MAMMALS
MEMBRANE PROTEINS
MEMBRANES
MICROSCOPY
NON-PEPTIDE C-N HYDROLASES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANS
PROTEINS
RADIOASSAY
RADIOIMMUNOASSAY
RADIOIMMUNODETECTION
RADIOIMMUNOLOGY
RADIOISOTOPES
RETINA
RUMINANTS
SENSE ORGANS
SODIUM COMPOUNDS
SUBCELLULAR DISTRIBUTION
TRACER TECHNIQUES
TRANSMISSION ELECTRON MICROSCOPY
VERTEBRATES