title: Acetyl-blocked N-terminal structures of sorbitol and aldehyde dehydrogenases.
abstract: Two new dehydrogenase structures, the 354-residue polypeptide chain of sorbitol dehydrogenase (from sheep liver) and the 500-residue polypeptide chain of cytoplasmic aldehyde dehydrogenase (from human liver), have blocked N-termini. The N-terminal peptides were purified by reverse-phase high-performance liquid chromatography and submitted to mass spectrometry after derivatization. They were also analyzed by dipeptidyl carboxypeptidase digestion, utilizing gas chromatography-mass spectrometry for dipeptide identifications. Results are consistent and establish that sorbitol dehydrogenase has N-terminal acetylalanine and aldehyde dehydrogenase N-terminal acetylserine in amino acid sequences that are compatible with estimates from chemical analyses. The two N-terminal residues found are typical of acetylated proteins in general, extend the group of known acetylated dehydrogenases, and show that these intracellular proteins are frequently N-terminally acetylated.
mesh_terms: D000107:Acetylation; D000409:Alanine / Q000031:analogs & derivatives* / Q000032:analysis; D000444:Aldehyde Dehydrogenase; D000445:Aldehyde Oxidoreductases / Q000032:analysis*; D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D010450:Endopeptidases; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D007064:L-Iditol 2-Dehydrogenase / Q000032:analysis*; D008099:Liver / Q000201:enzymology; D013058:Mass Spectrometry; D010446:Peptide Fragments / Q000302:isolation & purification*; D012694:Serine / Q000031:analogs & derivatives* / Q000032:analysis; D012756:Sheep; D013401:Sugar Alcohol Dehydrogenases / Q000032:analysis*
chemical_list: D010446:Peptide Fragments; C010530:N-acetylalanine; D012694:Serine; D013401:Sugar Alcohol Dehydrogenases; D007064:L-Iditol 2-Dehydrogenase; D000445:Aldehyde Oxidoreductases; D000444:Aldehyde Dehydrogenase; D010450:Endopeptidases; C020071:dipeptidyl carboxypeptidase; D000409:Alanine; C012162:N-acetylserine