Pronase is a commercially available mixture of proteases isolated from the extracellular fluid of Streptomyces griseus. Activity extends to both denatured and native proteins leading to complete or nearly complete digestion into individual amino acids. Pronase is a commercially available mixture of proteases isolated from the extracellular fluid of Streptomyces griseus. Activity extends to both denatured and native proteins leading to complete or nearly complete digestion into individual amino acids.