N-Terminal Amino Acid Sequences and Comparison of DMSP Lyases from Pseudomonas Doudoroffii and Alcagenes Strain M3A

摘要: A comparative in vitro study of the DMSP lyases from an estuarine isolate, Alcaligenes strain M3A and a marine organism, Pseudomonas doudoroffii has been carried out. The enzymes both organisms were induced to high levels by aeration, but unlike Alcaligenes, P. enzyme was easily inactivated vivo processes not yet understood. bound phenyl-Sepharose CL-4B could then be purified hydrophobic, anion exchange gel filtration chromatography. minor form (isozyme) lyase (DL-2) detected Alcaligenes; its size subunit composition similar major isoform (DL-1) as K m for DMSP. Polyclonal antibodies raised against equally reactive enzymes. Western blots SDS-polyacrylamide gels together with analysis showed that monomers 48 kDa. had (1 2 mM) v max (ca. 500 units/mg protein) Methyl-3-mercaptopropionate (MMPA) inhibitory activity organisms. Cyanide p-chloromercuri-benzoate inhibited vitro; unaffected. Based on results kinetic inhibitor studies, working model DMS production, which includes postulated DMSP-binding protein doudoroffii, presented. N-terminal amino acid sequences 75% homology each other first 20 residues, 90% 10 residues suggesting region these two bacteria is highly conserved. no significant degree any existing database.