A substance effecting differentiation in Streptomyces griseus. Purification and properties

A conidium-producing variant of Streptomyces griseus, strain 45-H, produces a substance, factor C, which is capable of inducing conidium formation in the hyphae of a conidium-non-producing mutant, strain 52-1. Factor C can be determined quantitatively on the basis of this biological effect. The biologically active substance can be purified by ion-exchange chromatography on cellulose phosphate combined with affinity chromatography on DNA-agarose. The purified substance is concentrated at least 1700 times. The molecular weight of factor C, estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate, is about 34500. On determining the amino acid composition of factor C 60% of the amino acids were found to be hydrophobic.