Rajamohanan P R, Ganapathy S, Vyas P R, Ravikumar A, Deshpande M V
Division of Physical Chemistry, National Chemical Laboratory, Pune, India.
J Biochem Biophys Methods. 1996 Feb 5;31(3-4):151-63. doi: 10.1016/0165-022x(95)00033-n.
The time-course hydrolysis of colloidal chitin by the chitinase complex isolated from Myrothecium verrucaria was monitored using solution and solid-state 13C-NMR spectroscopy. The solution NMR studies showed the presence of N-acetylglucosamine (GlcNAc) as the sole product of hydrolysis. Solid-state 13C CP/MASS studies, on the other hand, indicated the presence of high molecular weight oligomers as well as GlcNAc. The linewidth of the C1 carbon of the oligomers obtained after hydrolysis is found to be less than that of the unhydrolyzed sample. The linewidths calculated from the spin-spin relaxation times (T2) of colloidal chitin and its products of hydrolysis were in the restricted range of 40-50 Hz, compared with the observed linewidths of 143-123 Hz. Peak area measurement on monomer to polymer/oligomer indicated an initial slow formation of the monomer, GlcNAc. From the NMR data, the involvement of endo-enzymes in the initial phase of hydrolysis is suggested.
使用溶液和固态13C-NMR光谱监测了从疣孢漆斑菌中分离出的几丁质酶复合物对胶体几丁质的时程水解。溶液NMR研究表明，N-乙酰葡糖胺（GlcNAc）是唯一的水解产物。另一方面，固态13C CP/MASS研究表明存在高分子量低聚物以及GlcNAc。水解后得到的低聚物的C1碳的线宽小于未水解样品的线宽。根据胶体几丁质及其水解产物的自旋-自旋弛豫时间（T2）计算出的线宽在40-50 Hz的受限范围内，而观察到的线宽为143-123 Hz。单体与聚合物/低聚物的峰面积测量表明，单体GlcNAc最初形成缓慢。根据NMR数据，提示内切酶参与了水解的初始阶段。
