Catalogo Articoli (Spogli Riviste)

OPAC HELP

Titolo:
Kinetics and mechanism of St I modification by peroxyl radicals
Autore:
Campos, AM; Lissi, EA; Vergara, C; Lanio, ME; Alvarez, C; Pazos, I; Morera, V; Garcia, Y; Martinez, D;
Indirizzi:
Univ Santiago Chile, Fac Chem & Biol, Dept Chem, Santiago 33, Chile Univ Santiago Chile Santiago Chile 33 iol, Dept Chem, Santiago 33, Chile Univ Santiago Chile, Fac Sci, Dept Biol, Santiago 33, Chile Univ Santiago Chile Santiago Chile 33 Sci, Dept Biol, Santiago 33, Chile Univ Havana, Fac Biol, Dept Biochem, Havana, Cuba Univ Havana Havana Cuba iv Havana, Fac Biol, Dept Biochem, Havana, Cuba Ctr Genet Engn & Biotechnol, Havana, Cuba Ctr Genet Engn & Biotechnol Havana Cuba Engn & Biotechnol, Havana, Cuba
Titolo Testata:
JOURNAL OF PROTEIN CHEMISTRY
fascicolo: 3, volume: 18, anno: 1999,
pagine: 297 - 306
SICI:
0277-8033(199904)18:3<297:KAMOSI>2.0.ZU;2-D
Fonte:
ISI
Lingua:
ENG
Soggetto:
SEA-ANEMONE STICHODACTYLA; OXYGEN RADICALS; PROTEIN DAMAGE; HEMOLYTIC-ACTIVITY; STICHOLYSIN-I; INACTIVATION; DEGRADATION; HELIANTHUS; CYTOLYSIN;
Keywords:
toxin; Sticholysin; peroxyl radicals; hemolytic activity;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Life Sciences
Citazioni:
15
Recensione:
Indirizzi per estratti:
Indirizzo: Campos, AM Univ Santiago Chile, Fac Chem & Biol, Dept Chem, POB 40, Santiago 33, Chile Univ Santiago Chile POB 40 Santiago Chile 33 antiago 33, Chile
Citazione:
A.M. Campos et al., "Kinetics and mechanism of St I modification by peroxyl radicals", J PROTEIN C, 18(3), 1999, pp. 297-306

Abstract

St I is a toxin present in the Caribbean Sea anemone Stichodactyla helianthus which is highly hemolytic in the nanomolar concentration range. Exposure of the toxin to free radicals produced in the pyrolysis of 2,2'-azobis(2-amidinopropane) hydrochloride leads to a progressive loss of hemolytic activity. This loss of hemolytic activity is accompanied by extensive modification of tryptophan residues. On the average, three tryptophan residues are modified by each inactivated toxin. The loss of hemolytic activity of St I takes place without significant changes in the protein structure, as evidenced by the similarity of the fluorescence and CD spectra of native and modified proteins. Also, the native and modified ensembles present a similar resistance to their denaturation by guanidinium chloride. The hemolytic behavior and the performance of the toxin at the single-channel level when incorporated to black lipid membranes suggest that the modified ensemble can be considered as composed of inactive toxins and active toxins whose behavior is similar to that of the native proteins. These results, together with the lack of induction time in the activity loss, suggest that the fall of hemolytic activity takes place by an all-or-nothing inactivation mechanism in which the molecules become inactive when a critical amino acid residue is modified.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 27/01/20 alle ore 01:46:59