Asunto(s)
Proteínas Arqueales , Péptido Hidrolasas/aislamiento & purificación , Pyrococcus furiosus/enzimología , Proteínas Recombinantes de Fusión/aislamiento & purificación , Cromatografía Liquida/métodos , Clonación Molecular , Electroforesis en Gel de Poliacrilamida , Peso Molecular , Péptido Hidrolasas/genética , Péptido Hidrolasas/metabolismo , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismoAsunto(s)
Endopeptidasas/aislamiento & purificación , Thermotoga maritima/enzimología , Secuencia de Aminoácidos , Biopolímeros , Cromatografía Liquida/métodos , Endopeptidasas/química , Endopeptidasas/metabolismo , Microscopía Electrónica , Datos de Secuencia Molecular , Homología de Secuencia de AminoácidoRESUMEN
A novel homomultimeric protease (> 669 kDa), based on 31 kDa subunits, was purified from cell extracts of the hyperthermophilic bacterium Thermotoga maritima. This protease exhibits activity toward chymotrypsin and trypsin substrates, optimally at 90 degrees C and pH 7.1, and has a half-life of 36 min at 95 degrees C. Transmission electron microscopy established that the protease consists of a large globular assembly which appears circular from the front view. The function of this protease in T. maritima remains unclear, although putative homologs include a 29 kDa antigen from Mycobacterium tuberculosis and a 31 kDa monomer of a high molecular weight bacteriocin produced by Brevibacterium linens [Valdes-Stauber, N. and Scherer, S. (1996) Appl. Environ. Microbiol. 62, 1283-1286]. The relationship of these mesophilic proteins to the T. maritima protease suggests that their antibacterial activity may involve elements of proteolysis, and raises the prospect for antimicrobial ecological strategies in hyperthermophilic niches.
