Volkov P V, Rozhkova A M, Semenova M V, Zorov I N, Sinitsyn A P
Bach Institute of Biochemistry, Russian Academy of Sciences, Moscow, 119071, Russia.
Biochemistry (Mosc). 2013 Oct;78(10):1180-9. doi: 10.1134/S0006297913100131.
Here we report the first isolation to homogeneous forms of two glucoamylases from the fungus Penicillium verruculosum and their study in comparison with known glucoamylases from Aspergillus awamori and Aspergillus niger. Genes that encode glucoamylases from P. verruculosum were cloned and expressed in the fungus Penicillium canescens, and the recombinant glucoamylases were obtained with subsequent study of their molecular weights, isoelectric points, optimal temperature and pH values, and stability. The catalytic activities of the recombinant glucoamylases were determined in relation to soluble potato starch. Changes in molecular mass distribution and content of low molecular weight products during starch hydrolysis by glucoamylases from P. verruculosum, A. awamori, and A. niger were studied. An exo-depolymerization mechanism was established to be the pathway for destruction of starch by the glucoamylases.
在此，我们报告了首次从疣孢青霉中分离出两种糖化酶的均一形式，并将其与泡盛曲霉和黑曲霉中已知的糖化酶进行比较研究。克隆了编码疣孢青霉糖化酶的基因，并在渐变色青霉中表达，获得了重组糖化酶，并随后研究了它们的分子量、等电点、最适温度和pH值以及稳定性。测定了重组糖化酶相对于可溶性马铃薯淀粉的催化活性。研究了疣孢青霉、泡盛曲霉和黑曲霉的糖化酶在淀粉水解过程中低分子量产物的分子量分布和含量变化。确定了外切解聚机制是糖化酶破坏淀粉的途径。
