What question did this study set out to answer?

To determine whether glucokinase serves as the alloxan-sensitive glucose sensor in pancreatic beta-cells and elucidate the mechanism behind hexose-mediated protection.

October 1, 1986Diabetes

Identification of Glucokinase as an Alloxan-Sensitive Glucose Sensor of the Pancreatic β-Cell

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Authors

MMMartin D. MeglassonUniversity of Massachusetts Chan Medical School PBPamela Trueheart BurchCalifornia University of Pennsylvania DBDonna K BernerThe University of Texas MD Anderson Cancer Center

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Implication

In vitro study demonstrates alloxan-induced inactivation of glucokinase in pancreatic islets, indicating its central function as a beta-cell glucose sensor.

Key Points

To determine whether glucokinase serves as the alloxan-sensitive glucose sensor in pancreatic beta-cells and elucidate the mechanism behind hexose-mediated protection.
Assessed alloxan-induced glucokinase inactivation in intact, isolated pancreatic islets incubated in vitro with or without 30 mM glucose.
Tested inactivation kinetics and protection by hexoses, glucose anomers, and N-acetylglucosamine using glucokinase partially purified from transplantable insulinomas and rat liver.
Alloxan inactivated purified glucokinase with a half-maximal effect at 2 to 4 µM, which was prevented in intact islets by 30 mM glucose.
Hexoses antagonized glucokinase inactivation with a potency order of glucose > mannose > 2-deoxyglucose, with the alpha-anomer of glucose providing stronger protection than the beta-anomer.
N-acetylglucosamine failed to protect glucokinase from alloxan, demonstrating that alloxan targets a non-active site and glucose protects through an induced conformational change.

Cite This Study

Meglasson et al. (1986) studied this question.

synapsesocial.com/papers/6a91978373240bb033f075c5 https://doi.org/10.2337/diab.35.10.1163

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Implication

In vitro study demonstrates alloxan-induced inactivation of glucokinase in pancreatic islets, indicating its central function as a beta-cell glucose sensor.

Identification of Glucokinase as an Alloxan-Sensitive Glucose Sensor of the Pancreatic β-Cell

Discussion

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Implication

Key Points

Cite This Study

Identification of Glucokinase as an Alloxan-Sensitive Glucose Sensor of the Pancreatic β-Cell

Discussion

Member takes

Implication

Key Points

Cite This Study

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