Biologia, Bratislava, 57/Suppl. 11: 149-154, 2002.

ISSN 0006-3088 (Biologia).

 

Full Paper

Hepatic a-amylase in rat.

 

Kyoko Noguchi, Keiko Horiuchi-Toyota, Yoko Shiga & Hiroshi Akanuma*

Department of Life Sciences, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Meguro-ku, Tokyo, 153-8902 Japan; tel.: ++ 81 354544392, fax: ++ 81 354546998, e-mail: cakanum@m.ecc.u-tokyo.ac.jp

* corresponding author

Received: October 4, 2001 / Accepted: February 22, 2002

 

Abstract

a-Amylase activity and malto-oligosaccharides have long been described without isolation of any relevant enzyme in mammalian liver. We developed a micro-assay method for malto-oligosaccharides and effectively applied it to the study of hepatic amylolysis and isolation of an a-amylase from rat liver. The liver showed high a-amylase activity, high enough to account for the whole glycogenolytic activity in the liver. The isolated enzyme was digested with lysylendopeptidase and the major peptide fragments were sequenced. Complete amino acid sequencing was based on the full coding sequence of its mRNA determined by RT-PCR (Accession number: AB057450). The hepatic neutral amylolytic activity is so high that we expect the amylolytic pathway to be significant in glycogen metabolism in the liver.

 

Key words: rat, liver, alpha-amylase, cDNA sequence, oligosaccharide, O-ethylhydroxylamine.