Amylose, branching enzymes

Borovsky, D., Smith, E. E., and Whelan, W. J. 1975. Purification and properties of potato 1,4-a-D-glucan 1,4-a-D-glucan, 6-a-(l,4-a-D-glucano)-transferase. Evidence a dual catalytic function in amylose branching enzyme. Eur. J. Biochem. 59, 615-625. 

Hizukuri, S., Takeda, Y, Yasuda, M., Suzuki, A. (1981). Multi-branched nature of amylose and the action of de-branching enzymes. Carbohydr. Res., 94,205-213. 

Hofvander, P, Andersson, M., Larsson, C. -T., Larsson, H. (2004). Field performance and starch characteristics of high-amylose potatoes obtained by antisense gene targeting of two branching enzymes. Plant Biotechnology Journal, 2, 311-320. 

This mutation also presents another approach to obtaining a high-amylose starch. As will be described later, mutations of branching enzyme can lead to production of not only more amylose, but also of amylopectin molecules with fewer and longer chains, and having properties similar to those of amylose. 

Assay procedures there are three accepted methods in assaying branching enzyme (BE). One measures the decrease in absorbance of the glucan-I3 complex that results from the branching of amylose or amylopectin. The assay mixture containing amylose or amylopectin is incubated and aliquots are taken and iodine reagent is added.35,247 The decrease of absorbance is measured at 660 nm for amylose and at 530 nm for amylopectin. 

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