Enzymatic kinetic of cellulose hydrolysis - Inhibition by ethanol and cellobiose
Enzymatic kinetic of cellulose hydrolysis - Inhibition by ethanol and cellobiose
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DOI：
10.1007/s12010-005-0005-5
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发表时间：
2005-07-01
影响因子：
3
通讯作者：
Dias, AA
中科院分区：
文献类型：
--
作者：
Bezerra, RMF;Dias, AA
研究了乙醇对里氏木霉纤维素酶的影响，以定量和澄清这种抑制类型。为了确定粗纤维素酶和纯化的外切葡聚糖酶Cel 7A的抑制参数，使用积分Michaelis-Menten方程假设存在两种抑制剂：纤维二糖作为反应产物和乙醇作为纤维素发酵的可能生物产物，发现粗酶水解纤维素遵循考虑乙醇的非竞争性抑制的模型，而Cel 7A是非常轻微的竞争性抑制。粗纤维素酶比外切葡聚糖酶Cel 7A（K-icl = 1.6 × 10（15）mM）受到更多的抑制（K-iul = K-icl = 151.9 mM）。此外，计算的抑制常数表明，纤维二糖抑制比乙醇抑制更有效的粗酶以及外切葡聚糖酶Cel 7A。
The ethanol effect on the Trichoderma reesei cellulases was studied to quantify and clarify this inhibition type. To determine inhibition parameters of crude cellulase and purified exoglucanase Cel7A, integrated Michaelis-Menten equations were used assuming the presence of two inhibitors: cellobiose as the reaction product and ethanol as a possible bioproduct of cellulose fermentation.It was found that hydrolysis of cellulose by crude enzyme follows a model that considers noncompetitive inhibition by ethanol, whereas Cel7A is very slightly competitively inhibited. Crude cellulase is much more inhibited (K-iul = K-icl = 151.9 mM) than exoglucanase Cel7A (K-icl = 1.6 x 10(15) mM). Also, calculated inhibition constants showed that cellobiose inhibition is more potent than ethanol inhibition both for the crude enzyme as well as exoglucanase Cel7A.