Purification, characterization, immunolocalization and structural analysisof the abundant cytoplasmic beta-amylase from Calystegia sepium (hedge bindweed) rhizomes

An abundant catalytically active beta -amylase (EC 3.2.1.2) was isolated fr om resting rhizomes of hedge bindweed (Calystegia sepium). Biochemical anal ysis of the purified protein, molecular modeling, and cloning of the corres ponding gene indicated that this enzyme resembles previously characterized plant beta -amylases with regard to its amino-acid sequence, molecular stru cture and catalytic activities. Immunolocalization demonstrated that the be ta -amylase is exclusively located in the cytoplasm. It is suggested that t he hedge bindweed rhizome beta -amylase is a cytoplasmic vegetative storage protein.