Identification of a new binding protein for crotoxin and other neurotoxic phospholipase A sub 2 s on brain synaptic membranes

Journal Article · Tue Dec 03 04:00:00 EST 1991 · Biochemistry; (United States)

OSTI ID:5559096

Yen, Chonho ^[1]; Tzeng, Muchin ^[2]

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1. National Taiwan Univ., Taipei (Taiwan)
2. National Taiwan Univ., Taipei (Taiwan) Academia Sinica, Taipei (Taiwan)

Crotoxin and other neurotoxic phospholipase A{sub 2}s exert neurotoxicity by acting primarily at the presynaptic level. Strong binding of crotoxin and several other to synaptic membranes has been demonstrated previously. In this study the authors used simple chemical cross-linking techniques to identify the neuronal membrane molecules involved in the binding of these toxins. After {sup 125}I-crotoxin had bound to synaptosomes from guinea pig brain, treatment with disuccinimidyl suberate, disuccinimidyl dithiobis(propionate) or ethylene glycol bis(succinimidyl succinate) resulted in the formation of a predominant radioactive conjugate of {approximately}60 kDa, which was different from the conjugate formed by photoaffinity labeling technique in a previous report. The membrane component in the conjugate was shown to be a single-chain protein {approximately}45 kDa. In subfractions of synaptosomes, this binding protein was mostly found in the synaptic membrane fraction and was not present in the mitochondrial fraction. Plasma membranes from several nonneural tissues also did not contain this binding protein. Unmodified crotoxin inhibited the formation o this adduct with an IC{sub 50} of around 1 {times} 10{sup {minus}8} M. Mojave toxin and some other phospholipase A{sub 2}s were also highly inhibitory to this conjugation, and notexin and others were less effective, while {beta}-bungarotoxin and pancreatic PLA{sub 2} were totally ineffective. They concluded that a new protein of 45 kDa specifically present in neuronal membranes is another major molecule responsible for the binding of crotoxin and other phospholipase A{sub 2}s.

• OSTI ID: 5559096
• Journal Information: Biochemistry; (United States), Journal Name: Biochemistry; (United States) Vol. 30:48; 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
ANIMAL CELLS
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
CELL CONSTITUENTS
CELL MEMBRANES
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
HALIDES
HALOGEN COMPOUNDS
HAZARDOUS MATERIALS
HYDROLASES
INORGANIC PHOSPHORS
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
IODIDES
IODINE 125
IODINE COMPOUNDS
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
MATERIALS
MEMBRANE PROTEINS
MEMBRANES
MITOCHONDRIA
NERVE CELLS
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PEPTIDE HYDROLASES
PHOSPHORS
PROTEINS
RADIOISOTOPES
RADIORECEPTOR ASSAY
REPTILES
SNAKES
SODIUM COMPOUNDS
SODIUM IODIDES
SOMATIC CELLS
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
VENOMS
VERTEBRATES