Beldman G, Voragen A G, Rombouts F M, Searle-van Leeuwen M F, Pilnik W
Department of Food Science, Agricultural University, De Dreyen 12, 6703 BC Wageningen.
Biotechnol Bioeng. 1987 Aug 5;30(2):251-7. doi: 10.1002/bit.260300215.
Adsorption on crystalline cellulose of six endoglucanases (Endo I, II, III, IV, V and VI; 1, 4-beta-D-glucan glucanohydrolase, EC 3.2.1.4) and two exoglucanases (Exo II and III; 1,4-beta-D-glucan cellobiohydrolase, EC 3.2.1.92), purified from a commercial cellulase preparation of Trichoderma viride origin, was studied. Endo I, III, and V adsorbed strongly on Avicel cellulose, while adsorption of Endo II, IV, and VI was much lower. Also, the two exoglucanases could be divided into one enzyme (Exo III) that had a high adsorption affinity and another enzyme (Exo II) that adsorbed only moderately. Adsorption data fitted the Langmuir-type adsorption isotherm. However, adsorption was only partially reversible with respect to dilution. No relation could be found between adsorption affinity and degree of randomness in cellulose hydrolysis, measured as the diversity of released hydrolytic products. Kinetic measurements indicated that only part of the adsorbed enzyme molecules are hydrolytically active.
研究了从里氏木霉来源的商业纤维素酶制剂中纯化得到的六种内切葡聚糖酶（内切葡聚糖酶I、II、III、IV、V和VI；1,4-β-D-葡聚糖葡聚糖水解酶，EC 3.2.1.4）和两种外切葡聚糖酶（外切葡聚糖酶II和III；1,4-β-D-葡聚糖纤维二糖水解酶，EC 3.2.1.92）在结晶纤维素上的吸附情况。内切葡聚糖酶I、III和V在微晶纤维素上强烈吸附，而内切葡聚糖酶II、IV和VI的吸附则低得多。此外，两种外切葡聚糖酶可分为一种具有高吸附亲和力的酶（外切葡聚糖酶III）和另一种吸附程度适中的酶（外切葡聚糖酶II）。吸附数据符合朗缪尔型吸附等温线。然而，就稀释而言，吸附只是部分可逆的。在纤维素水解的随机性程度（以释放的水解产物的多样性来衡量）与吸附亲和力之间未发现相关性。动力学测量表明，只有部分吸附的酶分子具有水解活性。
