Abstract
Proteins in the culture supernatant of Staphylococcus aureus PS 47 were subjected to Sephadex chromatography. In the early stage of the cultivation, staphylokinase appeared to have a molecular weight of 15,000 and in the later stage it appeared to have a molecular weight of 320,000. The staphylokinase having a lower molecular weight (type A) converted into one having a higher value (type B) during the course of cultivation. It was demonstrated that conversion of type A into type B took place in vitro (monitored by gel filtration after the two types of staphylokinases were mixed), and it was observed that type B reverted to type A when type B was treated with KCl or detergent. Type B seems to be a complex form of type A and some high-molecular-weight substance.