Merck, 539480-100MGCN, Proteinase K from Tritirachium album

Serine protease that exhibits strong proteolytic activity on a wide variety of denatured and native proteins of high molecular weight. Because of its rapid proteolytic inactivation of endogenous nucleases, it can be used for isolation of mRNA and high molecular weight DNA. Preferentially cleaves bonds next to the carbonyl group of N-substituted hydrophobic, aliphatic, and aromatic amino acids. Inhibited by DFP, Hg²⁺, and PMSF. Not inactivated by metal chelators, sulfhydryl reagents, TLCK, or TPCK.