Arrangement of the disulphide bridges in human low-Mr kininogen.

Transposon mutant strains which were affected in bile acid catabolism were isolated from four Pseudomonas spp. Two of the mutant groups isolated were found to accumulate 12 alpha-hydroxyandrosta-1,4-diene-3,17-dione as the major product from deoxycholic acid. Strains in one of these two groups were able to grow on steroids such as chenodeoxycholic acid, which lacks a 12 alpha-hydroxy function, whereas the one member of the second group could not. With chenodeoxycholic acid, this latter strain accumulated a yellow muconic-like derivative, tentatively identified as 3,7-dihydroxy-5,9,17-trioxo-4(5),9(10)-disecoandrosta-1(10)2 -dien-4-oic acid. Members of two further mutant groups accumulated either 12 beta-hydroxyandrosta-1,4-diene-3,17-dione or 3,12 beta-dihydroxy-9(10)-secoandrosta-1,3,5(10)-triene-9,17-dione as the major product from deoxycholic acid. The relationship between the catabolism of m- and p-cresol, 3-ethylphenol and the bile acids was also examined.