Open AccessStarch Phosphorylase Inhibitor Is β-Amylase
Author(s) -
Shu-Mei Pan,
TienJye Chang,
Rong-Huay Juang,
Jun-Ming Su
Publication year - 1988
Publication title -
plant physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.554
H-Index - 312
eISSN - 1532-2548
pISSN - 0032-0889
DOI - 10.1104/pp.88.4.1154
Subject(s) - starch , amylase , glycogen phosphorylase , ipomoea , biochemistry , alpha amylase , chemistry , enzyme , food science , biology , botany
The proteinaceous noncompetitive inhibitor of starch phosphorylase isolated from the root of sweet potato (Ipomoea batatas [L.] Lam.) (TC Chang, JC Su 1986 Plant Physiol 80: 534-538) has been identified as a beta-amylase. The starch phosphorylase inhibitor and beta-amylase activities copurified to give a protein indistinguishable from commercial beta-amylase by electrophoretic and immunological methods, and the two activities showed parallel responses in pH, temperature, and inhibitor sensitivity tests. The amylolytic pattern of the inhibitor corresponded to that of beta-amylase and its inhibitory effect toward starch phosphorylase was due to neither deprivation of starch, the primer for the phosphorylase assay, nor the inhibitory effect of amylolytic products.