[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]
| Autor: | T L, Bushueva, O I, Uroshevich, N A, Maĭsurian, N V, Mirimanova, A G, Tonevitskiĭ |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
Protein Synthesis Inhibitors
Osmolar Concentration Temperature Tryptophan Ricin Hydrogen-Ion Concentration Catalysis Ribosome Inactivating Proteins Type 2 Spectrometry Fluorescence Chromatography Gel Ribosome Inactivating Proteins Type 1 Diphtheria Toxin Plant Preparations Plant Proteins Toxins Biological |
| Zdroj: | Molekuliarnaia biologiia. 25(2) |
| ISSN: | 0026-8984 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|