title: Structural and immunochemical properties of rat liver tyrosine aminotransferase.
abstract: Our results show for the first time sequence data of the N-terminal part of tyrosine aminotransferase. This unblocked form of TATase, which has never been detected before, starts with a serine. This serine was found at position 29 of the primary structure of the enzyme deduced from the cDNA. We suggest that this free N-terminal amino acid is the extremity of a TATase form generated by proteolysis during the process of purification. Thus, proteolysis does not occur at the C-terminal as has been suggested before, but rather at the N-terminal region of the enzyme. To confirm this possibility, a peptide corresponding to the sequence of the seven carboxy-terminal amino acids of TATase was synthesized. It was coupled to ovalbumin or keyhole limpet hemocyanin, and the resulting conjugates were used to raise anti-peptide antibodies. The crude sera obtained were purified and their abilities to recognize TATase in ELISA and dot-blot experiments were proven. Our results demonstrate that the C-terminal part of the enzyme is present and well-recognized by the anti-peptide serum prepared. Furthermore, the anti-peptide serum reacts with TATase without inhibiting its enzymatic activity.
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D004797:Enzyme-Linked Immunosorbent Assay; D007106:Immune Sera / Q000276:immunology / Q000494:pharmacology; D008099:Liver / Q000201:enzymology*; D008969:Molecular Sequence Data; D051381:Rats; D014444:Tyrosine Transaminase / Q000032:analysis / Q000276:immunology / Q000378:metabolism
chemical_list: D007106:Immune Sera; D014444:Tyrosine Transaminase