Amino acid compositions and partial sequences of two types of alkaline serine proteases from Nocardiopsis dassonvillei subsp. prasina OPC-210.

protein engineering but also for practical purposes such as potential cleaning agents, food additives, and dehairing agents. Recently, we isolated many alkalophilic actinomycetes as in our previous paper.X) One of the interesting alkalophilic actinomycetes, Nocardiopsis dassonvillei subsp. prasina OPC-210, produced two types of alkaline serine proteases (NDP-I and NDP-II). We have already reported the purification and properties of these proteases, as well as the taxonomy of the alkalophilic actinomycete OPC-210.2) This paper deals with the amino acid compositions and partial amino acid sequences of NDP-I and NDP-II isolated from the culture filtrate of N. dassonvillei subsp. prasina OPC-210. Amino acid analyses of NDP-I (Mr 21,000) and NDP-II (Mr 36,000) were done on a Hitachi L-8500 amino acid analyzer equipped with a D2850 chromato-integrator after hydrolysis in evacuated, sealed test tubes at 110°C for 24 and 72hr with 6n HC1. Reduction and S-carboxymethylation of these proteases was done by the method of Crest field et al.3) Samples (NDP-I, 0.2nmol; NDP-II, O.l nmol) were reduced with dithiothreitol in the presence of 6m guanidine-HCl and carboxymethylated with iodoacetic acid. For separate