TY - JOUR
T1 - Actions of starch carbohydrases on chemically modified maltodextrins
AU - Parrish, F. W.
AU - Smith, E. E.
AU - Whelan, W. J.
N1 - Funding Information:
ACKNOWLEDGMENTS We thank ProfessorW . T. J. Morgan for making a Nuffield Foundation grant available to F. W. Parrish and the ScienceR esearchC ouncil for the award of a ResearchS tudentshipt o E. E. Smith. We also thank Imperial Chemical Industries Ltd for the loan of apparatus.
PY - 1970/3
Y1 - 1970/3
N2 - Three enzymes, potato phosphorylase, human salivary α-amylase and sweet potato β-amylase, have been studied for their actions on maltodextrins that were reduced or oxidized at C-1 of the reducing-end glucose unit. These modifications do not alter the ability of dilute solutions of the amylases to cleave the tetra-, penta-, and hexasaccharides much more rapidly than maltotriose. Modification of maltotriose, however, renders the molecule immune to the amylases. The affinities of maltotriose, -tetraose, and -pentaose as primers for potato phosphorylase in its reaction with α-glucose 1-phosphate are all diminished by chemical modification, especially by oxidation, and the modified tetraoses display the poor priming characteristics of maltotriose. It is suggested that phosphorylase and an efficient primer, such as maltotetraose, form a nondissociable complex from which the primer can only be displaced in a reaction with another such molecule.
AB - Three enzymes, potato phosphorylase, human salivary α-amylase and sweet potato β-amylase, have been studied for their actions on maltodextrins that were reduced or oxidized at C-1 of the reducing-end glucose unit. These modifications do not alter the ability of dilute solutions of the amylases to cleave the tetra-, penta-, and hexasaccharides much more rapidly than maltotriose. Modification of maltotriose, however, renders the molecule immune to the amylases. The affinities of maltotriose, -tetraose, and -pentaose as primers for potato phosphorylase in its reaction with α-glucose 1-phosphate are all diminished by chemical modification, especially by oxidation, and the modified tetraoses display the poor priming characteristics of maltotriose. It is suggested that phosphorylase and an efficient primer, such as maltotetraose, form a nondissociable complex from which the primer can only be displaced in a reaction with another such molecule.
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U2 - 10.1016/0003-9861(70)90426-1
DO - 10.1016/0003-9861(70)90426-1
M3 - Article
C2 - 5435055
AN - SCOPUS:0014747421
VL - 137
SP - 185
EP - 189
JO - Archives of Biochemistry and Biophysics
JF - Archives of Biochemistry and Biophysics
SN - 0003-9861
IS - 1
ER -