[Features of the structure of catalytic subunits of toxins, inhibiting protein synthesis. I. The effect of pH and interaction with the B-chain of ricin]. / Osobennosti struktury kataliticheskikh sub''edinits toksinov, ingibiruiushchikh belkovyi sintez. I. Vliianie pH, vzaimodeistvie s B-tsep'iu ritsina.
Mol Biol (Mosk)
; 25(2): 422-30, 1991.
Article
em Ru
| MEDLINE
| ID: mdl-1881395
ABSTRACT
A comparative study of gelonin and A-chains of ricin, mistletoe lectin I and diphtheria toxin was undertaken. The effect of pH was studied on a) the conformation of the proteins under study using intrinsic fluorescence; b) interaction of these proteins with ricin B-chain using gel-filtration. Structural stability of the proteins was assessed according to denaturing action of guanidine hydrochloride and temperature, and localization of tryptophan residues was determined using fluorescence quenching by I-, Cs+ and acrylamide. All investigated proteins were shown to undergo the conformational changes when a environment became acidic. In comparison with an intact protein--gelonin, the A-chains of ricin, a mistletoe lectin and a diphtheria toxin are less stable. At pH less than 5.0 tryptophan residues became more accessible to quencher and a positive charge of the surrounding area increases (in the case of gelonin it is negatively charged). No reliable interaction of a ricin B-chain with both gelonin and A-chain of diphtheria toxin was observed. The interaction of a ricin B-chain with a A-chain of mistletoe lectin I is weaker than that with ricin A-chain and is practically pH-independent.
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Base de dados:
MEDLINE
Assunto principal:
Ricina
/
Toxinas Biológicas
/
Inibidores da Síntese de Proteínas
/
Preparações de Plantas
Idioma:
Ru
Revista:
Mol Biol (Mosk)
Ano de publicação:
1991
Tipo de documento:
Article