Multiple forms of starch branching enzyme of maize: evidence for independent genetic control
Multiple forms of starch branching enzyme of maize: evidence for independent genetic control
- BioChemical and Biophysical Research Communications, 80(3-4), p.169-175, 1978 .
PuriEication of starch branching enzymes from kernels of two nonlinked mutants of maize, sugary and amylose-extender, showed the basis of the two mutations to be associated with branching enzymes I and IIb, respectively. Branching enzyme I from sugary kernels purified as nonmutant branching enzyme I, but had an altered pattern of activity when amylose was used as a substrate. In addition to the typical fall in absorbance at high wavelengths (550-700 nm)of the amylose-iodine complex, branching of amylose by sugary branching enzyme I caused an increase in absorbance at low wavelengths (400-550 nm). Branching enzyme IIb was undetected in extracts of amylose-extender kernels, while branching enzymes I and IIa appeared unaltered. Low umprimed starch synthase activity was also observed in DEAE-cellulose fractions of amyloseextender maize, but this activity was regenerated by the addition of any branching enzyme
PuriEication of starch branching enzymes from kernels of two nonlinked mutants of maize, sugary and amylose-extender, showed the basis of the two mutations to be associated with branching enzymes I and IIb, respectively. Branching enzyme I from sugary kernels purified as nonmutant branching enzyme I, but had an altered pattern of activity when amylose was used as a substrate. In addition to the typical fall in absorbance at high wavelengths (550-700 nm)of the amylose-iodine complex, branching of amylose by sugary branching enzyme I caused an increase in absorbance at low wavelengths (400-550 nm). Branching enzyme IIb was undetected in extracts of amylose-extender kernels, while branching enzymes I and IIa appeared unaltered. Low umprimed starch synthase activity was also observed in DEAE-cellulose fractions of amyloseextender maize, but this activity was regenerated by the addition of any branching enzyme