Proteinase K is a highly reactive nonspecific serine protease that belongs to the subtilisin family of proteins. It cleaves at the carboxylic acid side of aliphatic, aromatic, or hydrophobic amino acids. Proteinase K is capable of inactivating RNases and DNases and is used in the isolation or preparation of high molecular weight nucleic acids. Proteinase K is also useful for helping to characterize enzymes, due to its cleavage specificity. This enzyme was designated proteinase K because of its ability to hydrolyze keratin. Proteinase K is stable in a wide variety of detergents and buffer salts and at various temperatures and pH. The isoelectric point of proteinase K is 8.9.

Proteinase K is a highly reactive nonspecific serine protease that belongs to the subtilisin family of proteins. It cleaves at the carboxylic acid side of aliphatic, aromatic, or hydrophobic amino acids. Proteinase K is capable of inactivating RNases and DNases and is used in the isolation or preparation of high molecular weight nucleic acids. Proteinase K is also useful for helping to characterize enzymes, due to its cleavage specificity. This enzyme was designated proteinase K because of its ability to hydrolyze keratin. Proteinase K is stable in a wide variety of detergents and buffer salts and at various temperatures and pH. The isoelectric point of proteinase K is 8.9.

RNase A, isolated from bovine pancreas, degrades single-stranded RNA at the C and U residues; therefore, RNase A is pyrimidine specific. Degradation occurs by cleaving the phosphodiester bond located between the 5’-ribose of the nucleotide and the phosphate group that is connected to the 3’-ribose of the neighboring pyrimidine.