The behaviour of Phanerochaete chrysosporium cellobiose dehydrogenase on adsorption to crystallineand amorphous celluloses
The behaviour of Phanerochaete chrysosporium cellobiose dehydrogenase on adsorption to crystallineand amorphous celluloses
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黄孢原毛平革纤维二糖脱氢酶对结晶和无定形纤维素的吸附行为
DOI：
10.1111/j.1470-8744.1997.tb00425.x
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发表时间：
1997
影响因子：
2.8
通讯作者：
K. Eriksson
中科院分区：
文献类型：
--
作者：
M. Samejima;T. Ohkubo;K. Igarashi;A. Isogai;S. Kuga;J. Sugiyama;K. Eriksson
纤维二糖脱氢酶（CDH）吸附到纤维素上以前已有报道。然而，CDH吸附的纤维素的结构类型尚未研究。在本研究中，我们比较了CDH的行为时，它吸附在高度结晶的纤维素微纤维从Valonia macrophysa和完全无定形纤维素制备的溶液中的Avicel在SO2/胺系统。CDH在Valonia和无定形纤维素上的吸附等温线均符合Langmuir吸附理论。无定形纤维素对CDH的最大吸附量远高于橡属纤维素。通过透射电子显微镜，用胶体金标记的抗体显示吸附在纤维素上的CDH的位置。通过使用这种技术，它表明，CDH吸附到Valonia纤维素是有限的无定形区域连接到结晶微纤维，而没有CDH被吸附到表面的高度结晶微纤维。此外，纤维素酶活性的连续监测表明，即使在Valonia纤维素的表面上也存在有限量的易受酶水解的结构。从这些观察，我们得出结论，纤维素的无定形区域似乎CDH吸附的首选网站，而CDH不吸附到高度结晶微纤维的表面。
The adsorption of cellobiose dehydrogenase (CDH) to cellulose has been previously reported. However, the structural type of cellulose on to which CDH is adsorbed has not been investigated. In the present study we have compared the behaviour of CDH when it adsorbs on the highly crystalline cellulose microfibrils from Valonia macrophysa and on the completely amorphous cellulose prepared from a solution of Avicel in the SO2/amine system. The isotherms of CDH adsorption to both Valonia and amorphous celluloses fit well with the Langmuir adsorption theory. However, the maximum adsorption of CDH to the amorphous cellulose was much higher than that to Valonia cellulose. The location of CDH adsorbed on cellulose was revealed with colloidal‐gold‐tagged antibodies by transmission electron microscopy. By using this technique it was demonstrated that CDH adsorption to Valonia cellulose was limited to the amorphous regions attached to the crystalline microfibrils, whereas no CDH was adsorbed to the surface of the highly crystalline microfibrils. Furthermore, continuous monitoring of cellulase activity showed that limited amounts of structures susceptible to enzymic hydrolysis exist even on the surface of Valonia cellulose. From these observations, we conclude that amorphous regions of cellulose seem to the preferred sites of CDH adsorption, whereas CDH is not adsorbed to the surface of highly crystalline microfibrils.