Bile acid coenzyme A: amino acid N-acyltransferase in the amino acid conjugation of bile acids

Methods Enzymol. 2005:400:374-94. doi: 10.1016/S0076-6879(05)00022-4.

Abstract

Bile acids are converted to their glycine and taurine N-acyl amidates by enzymes in the liver in a two-step process. This increases their aqueous solubility, particularly in the acidic environment of the upper part of the small intestine. Bile acid coenzyme A (CoA) thioesters synthesized by bile acid CoA ligase (see Shonsey et al., 2005) are substrates of bile acid CoA:amino acid N-acyltransferases (BAT) in the formation of bile acid N-acyl amidates. This chapter describes the methods used to purify BAT from human liver, to isolate and clone cDNAs encoding BAT from human, mouse, and rat liver cDNA libraries, the expression of BAT, the assays used to measure BAT activity, and the chemical syntheses of bile acid N-acylamidates. In addition, an enzyme that catalyzes further metabolism of glycine-conjugated bile acids is described.

Publication types

  • Comment
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / chemistry
  • Acyltransferases / metabolism*
  • Amino Acid Sequence
  • Animals
  • Bile Acids and Salts / chemistry*
  • Bile Acids and Salts / metabolism
  • Chemistry Techniques, Analytical / methods*
  • Cloning, Molecular
  • Coenzyme A Ligases* / genetics
  • Coenzyme A Ligases* / isolation & purification
  • Coenzyme A Ligases* / metabolism
  • DNA, Complementary / genetics
  • Gas Chromatography-Mass Spectrometry
  • Glycine / chemistry*
  • Glycine / metabolism
  • Humans
  • Mice
  • Microsomes, Liver / enzymology*
  • Molecular Sequence Data
  • Molecular Structure
  • Phylogeny
  • Rats
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Spectrometry, Mass, Electrospray Ionization
  • Substrate Specificity

Substances

  • Bile Acids and Salts
  • DNA, Complementary
  • Recombinant Proteins
  • Acyltransferases
  • Coenzyme A Ligases
  • bile acid-CoA ligase
  • Glycine