Naslov
Properties and amino terminal part sequence of extracellular alpha-amylase from Streptomyces rimosus

Autori
Vukelić, Bojana ; Ritonja, Anka ; Pokorny, Mišo ; Vitale, Ljubinka

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Skup
Annual Meeting of Croatian Biochemists with International participation

Mjesto i datum
Zagreb, Hrvatska, 17.06.1993. - 18.06.1993

Vrsta sudjelovanja
Poster

Vrsta recenzije
Nije recenziran

Ključne riječi
alpha-amylase; amino acid sequence; Streptomyces rimosus

Sažetak
Alpha-amylase from culture filtrates of Streptomyces rimosus, oxytetracycline producing strain, was purified to homogeneity. It hydrolyzed soluble starch and amylopectin, having kinetic coefficient of kcat/Km of 231 and 139 ml mg-1sec-1, respectively. Optimal conditions for the activity were pH 5-6 and 47oC. The enzyme was shown to be an acidic monomer of relative molecular mass of 43 000, stable at pH 5-9 and up to 40oC. The presence of Ca2+ ions increased its stability. Isolated alpha-amylase was inhibited by thiol reagents and to some extent by chlating agents and anionic detergent, whereas activation by metal and chloride ions was not observed. Calcium and cobalt cations protected the nzyme from reagents which block SH-groups. Amino acid composition revealed the presence of three cysteins per molecule of enzyme, at least one of which participates in it activity. Determined amino acid sequence at the NH2-terminus, when aligned with the known sequences of alpha-amylase from other Streptomyces species showed 57-60 % homology. Immune serum specific for alpha-amylase from S. rimosus was prepared and used for determination of its relation to other alpha-amylases.

Izvorni jezik
Engleski

Znanstvena područja
Kemija

POVEZANOST RADA