This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via CrossRef Citing Articles via Google Scholar Google Scholar Articles by Weselake, R. J. Articles by Hill, R. D. Search for Related Content PubMed PubMed Citation Articles by Weselake, R. J. Articles by Hill, R. D. Agricola Articles by Weselake, R. J. Articles by Hill, R. D.

Articles

An Endogenous -Amylase Inhibitor in Barley Kernels ¹

Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8, Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2, Canada

Barley (Hordeum distichum cv Klages) kernels were shown to contain a factor that converted malted barley -amylase II to the -amylase III form. After purification by ammonium sulfate fractionation, ion exchange chromatography on DEAE-Sephacel, and gel-filtration on Bio Gel P60, the factor gave a single band of protein on isoelectric focusing. The purified factor inhibited hydrolysis of soluble starch by -amylase II from malted barley and germinated wheat (Triticum aestivum cv Neepawa). However, -amylase I from these cereals was not affected. The inhibitor was not dialyzable and was retained by a PM 10 ultrafiltration membrane suggesting a molecular weight greater than 10,000 daltons. Heat treatment of the inhibitor at 70°C for 15 minutes at pH 5.5 and 8.0 resulted in considerable loss of inhibitory activity.

¹ Partially supported by Grant A4689 from the Natural Sciences and Engineering Research Council of Canada. Paper No. 514 of the Grain Research Laboratory, Canadian Grain Commission, Winnipeg, Manitoba R3C 3G8 Canada. Paper No. 641 of the Department of Plant Science, University of Manitoba, Winnipeg, Manitoba R3T 2N2 Canada.

This article has been cited by other articles:

				I. Matsui and B. Svensson Improved Activity and Modulated Action Pattern Obtained by Random Mutagenesis at the Fourth beta -alpha Loop Involved in Substrate Binding to the Catalytic (beta /alpha )8-Barrel Domain of Barley alpha -Amylase 1 J. Biol. Chem., September 5, 1997; 272(36): 22456 - 22463. [Abstract] [Full Text] [PDF]