Purification and characterization of the extracellular α-amylase from Streptococcus bovis JB1

59Citations
Citations of this article
49Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

The extracellular α-amylase (1,4-α-D-glucanglucanohydrolase; EC 3.2.1.1) from maltose-grown Streptococcus bovis JB1 was purified to apparent homogeneity by ion-exchange chromatography (Mono Q). The enzyme had an isoelectric point of 4.50 and an apparent molecular mass of 77,000 Da, as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The enzyme was rich in acidic and hydrophobic amino acids. The 15-amino-acid NH2-terminal sequence was 40% homologous with the Bacillus subtilis saccharifying α-amylase and 27% homologous with the Clostridium acetobutylicum α-amylase. α-Amylase activity on soluble starch was optimal at pH 5.0 to 6.0. The enzyme was relatively stable between pH 5.5 and 8.5 and at temperatures below 50°C. When soluble potato starch was used as the substrate, the enzyme had a K(m) of 0.88 mg · ml-1 and a k(cat) of 2,510 μmol of reducing sugar · min-1 · mg of protein-1. The enzyme exhibited neither pullulanase nor dextranase activity and was 40 to 70% as active on amylopectin as on amylose. The major end products of amylose hydrolysis were maltose, maltotriose, and maltotetraose.

Cite

CITATION STYLE

APA

Freer, S. N. (1993). Purification and characterization of the extracellular α-amylase from Streptococcus bovis JB1. Applied and Environmental Microbiology, 59(5), 1398–1402. https://doi.org/10.1128/aem.59.5.1398-1402.1993

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free