首页 | 本学科首页   官方微博 | 高级检索  
检索        


Specificity of brain cathepsin D: cleavage of model peptides containing the susceptible Phe-Phe regions of myelin basic protein
Authors:N Marks  M Benuck  G Hashim
Abstract:Brain cathepsin D, purified by affinity chromatography on Sepharose pepstatin columns, was incubated with synthetic peptides corresponding to the susceptible regions of the myelin basic protein encompassing the two Phe-Phe bonds. One peptide, Leu-Gly-Arg-Phe-Phe-Gly-Gly, was cleaved by cathepsin D at the Phe-Phe bond while another, Val-His-Phe-Phe-Lys-Asn-Gly, was resistant to cleavage. To determine if this was a result of His flanking the Phe-Phe bond, or chain length on the N-terminal side, two decapeptides were synthesized differing only in the presence or absence of His adjacent to Phe. The results show that both of the decapapetides were cleaved by cathepsin D at the Phe-Phe linkages. In addition, prolonged incubation led to release of N-terminal Lys, indicating an additional cleavage at the Phe-Lys bond. In contrast to the limited cleavage by cathepsin D, pepsin split all four peptides. These results support earlier work on the limited proteolysis of basic protein at the Phe-Phe bond and suggest additional sites upon prolonged exposure. Such peptides may have utility as alternative substrates for basic protein or as models for subsequent synthesis of possible inhibitors of the enzyme.
Keywords:brain cathepsin D  cathepsin D specificity  basic proteins  myelin breakdown  peptides
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号