Voltammetric determination of dipeptidyl aminopeptidases I and IV

Dipeptidyl aminopeptidases I and IV have recently found wide practical application (polypeptide sequencing, clinical diagnostics) so it is necessary to extend present methods and work out new ones for determination of their activity. A new, voltammetric method for determination of peptidase activity is proposed, which allows optimization of the determination conditions according to the activity to be measured. The method has some advantages over the spectrophotometric methods, such as applicability to opaque solutions and higher sensitivity.     

Critical reactions in ripening of cheeses

A mathematical model has been developed for the key reactions taking place during cheese ripening. It includes growth and lysis of cells in the cheese matrix, cell-wall bound proteinases and intracellular peptidases that are released into cheese upon cell lysis, and the production of peptides and amino acids from casein in cheese. The model parameters have been estimated using published experimental data for cheddar cheese, and model simulations have been conducted to suggest effective means of reducing ripening times of cheeses. The time required for ripening of cheeses can be significantly reduced by carefully controlling the cell numbers at the beginning of cheese ripening and their proteinase and peptidase activities.     

发育中花生胚离体萌发和蛋白酶活性变化及脱落酸的影响

发育过程中花生胚氨肽醇有两个活性高峰，与贮藏蛋白质的两个合成高峰相吻合，发育晚期有微弱的羧肽酶活性出现，脱落酸能抑制离体胚萌发，抑制内肽酶和羧肽酶活性，但不抑制氨肽酶活性。发育早期离体胚萌发时贮藏蛋白质降解依赖于羧肽酶、Ａｃｔ－Ｄ和ＣＨＭ处理结果表明羧肽酸在成熟胚已预存但活性处于抑制状态。