Amylase binding to starch granules under hydrolysing and non-hydrolysing conditions

Dhital, Sushil, Warren, Frederick J., Zhang, Bin and Gidley, Michael J. (2014) Amylase binding to starch granules under hydrolysing and non-hydrolysing conditions. Carbohydrate Polymers, 113 97-107. doi:10.1016/j.carbpol.2014.06.063

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Author Dhital, Sushil
Warren, Frederick J.
Zhang, Bin
Gidley, Michael J.
Title Amylase binding to starch granules under hydrolysing and non-hydrolysing conditions
Journal name Carbohydrate Polymers   Check publisher's open access policy
ISSN 0144-8617
Publication date 2014-11-26
Sub-type Article (original research)
DOI 10.1016/j.carbpol.2014.06.063
Open Access Status
Volume 113
Start page 97
End page 107
Total pages 11
Place of publication Kidlington, Oxford, United Kingdom
Publisher Pergamon Press
Collection year 2015
Language eng
Abstract Although considerable information is available about amylolysis rate, extent and pattern of granular starches, the underlying mechanisms of enzyme action and interactions are not fully understood, partly due to the lack of direct visualisation of enzyme binding and subsequent hydrolysis of starch granules. In the present study, α-amylase (AA) from porcine pancreas was labelled with either fluorescein isothiocyanate (FITC) or tetramethylrhodamine isothiocyanate (TRITC) fluorescent dye with maintenance of significant enzyme activity. The binding of FITC/TRITC-AA conjugate to the surface and interior of granules was studied under both non-hydrolysing (0 °C) and hydrolysing (37 °C) conditions with confocal microscopy. It was observed that enzyme binding to maize starch granules under both conditions was more homogenous compared with potato starch. Enzyme molecules appear to preferentially bind to the granules or part of granules that are more susceptible to enzymic degradation. The specificity is such that fresh enzyme added after a certain time of incubation binds at the same location as previously bound enzyme. By visualising the enzyme location during binding and hydrolysis, detailed information is provided regarding the heterogeneity of granular starch digestion.
Keyword Alpha-amylase
Confocal microscopy
Enzyme binding
Starch granules
Surface structure
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Queensland Alliance for Agriculture and Food Innovation
Official 2015 Collection
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Citation counts: TR Web of Science Citation Count  Cited 10 times in Thomson Reuters Web of Science Article | Citations
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