Antibiotin factor

Wooley DW, Longsworth LG (1942) Isolation of an antibiotin factor from egg white. J. Biol. Chem. 142 285-290... 

D.W. Woolley and L. G. Longsworth, Isolation of an Antibiotin Factor from Egg... 

This is the clearest evidence there is at present to account for the effect of pimelic acid as a bacterial essential nutrient. The particular strains of C. dipMheriae which require pimelic acid as a nutrient are probably strains lacking the ability to synthesize biotin. And this defective synthetic power would appear to concern the fatty acid side chain of biotin, since when pimelic acid is provided, the rest of the molecule appears to be synthesized. This is supported by the finding that C. diphtheriae Allen strain, using pimelic acid, was not inhibited by the antibiotin factor avidin, whereas inhibition did occur when biotin was the external source of growth factor (see next section). (Cf. also 73a.)... 

The use of specific inhibitors operative against essential metabolites opens a new route of attack for the discovery of the external growth factor requirements of bacteria and other organisms. Once an essential metabolite is Imown it may be possible deliberately to design specific growth inhibitors (90) or to find naturally-occurring ones, like the antibiotin factor these specific inhibitors will then enable a rapid survey of bacteria to be made to reveal their requirements for the specific essential metabolite. 

Since the antibiotin factor does not inhibit those bacteria which synthesize biotin, the antibiotin factor appears to combine only with the externally supplied biotin and cannot penetrate effectively to the sites of biotin synthesis and utilization. This is analogous to the findings with the synthetic inhibitory growth factor analogs (e.g., pyrithiamin and thiamin, pantoyl taurine and pantothenic acid, pyridine-2-sulfonamide and nicotinamide) where the inhibitory action is largely confined to those otgan-isms which do not synthesize the growth factor. 

A study was made of the action of the antibiotin factor, avidin (62a), which indicated that the urea ring portion of biotin must be intact for combination between biotin and the antibiotin protein to take place the aliphatic side chain als,o seemed necessary. 

Growth-inhibitions by compounds structurally related to biotin have been observed. These are different in kind from the action of the antibiotin factor, where an inactive protein complex is formed. These structurally related anti-metabolites include biotin sulfone and desthiobiotin, their activities being related to the nutritional requirements of the organ-... 

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