Cytosolic bile acid-CoA conjugates (choloyl-CoA; chenodeoxycholoyl-CoA) react with the amino acids glycine and taurine, generating the corresponding bile salts and coenzyme A, catalyzed by BAAT (bile acid-CoA:amino acid N-acetyltransferase). In the body, this reaction occurs in hepatocytes and is the means by which bile acids recovered from the intestine are converted to bile salts before being released again into the bile (Kullak-Ublick et al. 2004; Trauner and Boyer 2002).
Chenodeoxycholoyl CoA reacts with glycine or taurine to form glycochenodeoxycholate or taurochenodeoxycholate, releasing CoASH. This reaction, which completes the de novo synthesis of bile salts from cholesterol in vivo, is catalyzed by BAAT (Bile acid CoA:amino acid N-acyltransferase - Falany et al. 1994) and occurs in the peroxisomal matrix (Solaas et al. 2000; Mihalik et al. 2002). In vivo, the relative amounts of glycochenodeoxycholate and taurochenodeoxycholate synthesized appear to be determined solely by the intracellular abundances of glycine and taurine (Russell 2003).
Choloyl CoA reacts with glycine or taurine to form glycocholate or taurocholate, releasing CoASH. This reaction, which completes the de novo synthesis of bile salts from cholesterol in vivo, is catalyzed by BAAT (Bile acid CoA:amino acid N-acyltransferase - Falany et al. 1994) and occurs in the peroxisomal matrix (Solaas et al. 2000; Mihalik et al. 2002). In vivo, the relative amounts of glycocholate and taurocholate synthesized appear to be determined solely by the intracellular abundances of glycine and taurine (Russell 2003).