Premium
PURIFICATION AND SOME PHYSICAL AND CHEMICAL PROPERTIES OF RED KIDNEY BEAN (PHASEOLUS VULGARIS) α‐AMYLASE INHIBITOR
Author(s) -
POWERS JOSEPH R.,
WHITAKER JOHN R.
Publication year - 1978
Publication title -
journal of food biochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.507
H-Index - 47
eISSN - 1745-4514
pISSN - 0145-8884
DOI - 10.1111/j.1745-4514.1978.tb00183.x
Subject(s) - amylase , sephadex , chemistry , biochemistry , phaseolus , chromatography , food science , biology , enzyme , botany
Red kidney bean contains more amylase inhibitor than do California white bean and cowpea while garbanzo bean and Westan and Westley lima beans do not contain inhibitor. Red kidney bean amylase inhibitor was purified to homogeneity by selective heat treatment (60°C) of a water extract at pH 4. 0, fractionation with ethanol and successive chromatography on DEAE‐ and CM‐cellulose chromatography. The inhibitor has an apparent molecular weight of 49,000 by Sephadex gel filtration and contains 8. 6% carbohydrate probably covalently linked via an amide linkage to asparagine. The inhibitor probably contains four subunits perhaps of three different types. The inhibitor is high in aspartic acid, glutamic acid, serine, threonine and valine, low in cysteine/cystine and does not contain proline. Stable 1:1 complex formation between inhibitor and porcine pancreatic α‐amylase was demonstrated by gel filtration on Sephadex G‐100. The inhibitor has activity against porcine pancreatic α‐amylase, human salivary α‐amylase, and Tenebrio molitor (yellow corn meal worm) larval midgut α‐amylase but is inactive against Bacillus subtilis α‐amylase, Aspergillus oryzae α‐amylase, barley α‐amylase and red kidney bean α‐amylase.