Studies on codehydrogenases I —Nature of growth factor "V”

Abstract

In 1917, Davis recognized that two growth factors are required by influenza bacilli. A few years later, Thjötta and Avery (1920, 1921) were able to confirm Davis’s data and named these substances “X” and “V” factors respectively. The “X” factor is actually well known chemically (Ghon and Preyss 1902-4, Davis 1917, etc.) and physiologically (Lwoff, A. 1936 a ). The so-called “growth factor V” has been studied by numerous workers (Davis 1917, 1921; Fildes 1921; Thjötta and Avery 1920, 1921; Rivers and Poole 1921; Thjötta 1924; and others) but its nature is still unknown. "Growth factor V” is found in yeast, blood corpuscles, and animal and vegetable tissues. It is water soluble, sensitive to heat, being destroyed by heating in alkaline but not in acid solutions. It passes through Berkefeld filters and collodion membranes, and is partially adsorbed by bone charcoal. It is destroyed by contact with fresh serum of certain animals in 4 hr. at 37°C., the destructive power of which can be removed by heating at 70°C. It is further known that vitamin C is unable to act as “V” factor.