All animals, except for the placental mammals, conjugate their bile acids exclusively with taurine. However, in certain of the placental mammals, glycine conjugates are also found. The basis for the appearance of glycine conjugation among the placental mammals was investigated. The reaction of choloyl-CoA with glycine and taurine, as catalysed by the soluble fraction from guinea-pig liver, had a high affinity for taurine and a poor affinity for glycine. The predominant synthesis of glycine conjugates in the guinea pig can be related to the fact that guinea-pig liver contains an unusually low concentration of taurine and a high concentration of glycine. Rabbits make exclusively glycine conjugates and their livers also contain low concentrations of taurine. However, the biochemical basis for their glycine conjugation is more straightforward than in the guinea pig in that the soluble fraction from rabbit liver has a high affinity for glycine and a poor affinity for taurine. Alternative-substrate-inhibition studies with glycine and taurine in soluble fractions from guinea-pig and rabbit liver revealed that glycine and taurine were mutually inhibitory. This suggests that there is only one enzyme for glycine and taurine conjugation in these tissues. The soluble fractions from bovine liver and human liver also made both glycine and taurine conjugates and evidence is presented that suggests that there is only one enzyme in these tissues too. Even the rat, which excretes mostly taurine conjugates, could make both glycine and taurine conjugates in vitro. However, in contrast with all of the placental mammals studied, the supernatant fraction from liver of the chicken, and other non-mammals, could not make glycine conjugates even in the presence of very high concentrations of glycine.
Skip Nav Destination
- PDF Icon PDF LinkFront Matter
- PDF Icon PDF LinkTable of Contents
- PDF Icon PDF LinkAdvertising
Research Article| August 15 1978
The biochemical basis for the conjugation of bile acids with either glycine or taurine
Donald A. Vessey
Donald A. Vessey
1Liver Studies Unit, Molecular Biology Division and Department of Medicine, Veterans Administration Hospital (151-K), San Francisco, CA 94121, U.S.A., and Departments of Medicine and Biochemistry, University of California Medical Center, San Francisco, CA 94143, U.S.A.
Search for other works by this author on:
Biochem J (1978) 174 (2): 621–626.
Donald A. Vessey; The biochemical basis for the conjugation of bile acids with either glycine or taurine. Biochem J 15 August 1978; 174 (2): 621–626. doi: https://doi.org/10.1042/bj1740621
Download citation file:
Don't already have an account? Register
Sign in to your personal account
You could not be signed in. Please check your email address / username and password and try again.
Could not validate captcha. Please try again.
Sign in via your InstitutionSign in via your Institution
Get Access To This Article
Buy This Article