[Biochemistry and structural biology of microbial enzymes and their medical applications].
Microbial enzymes were studied from two medicinal viewpoints. First, we examined proline-specific peptidases from pathogenic microorganisms. We found several proline-specific peptidases in pathogenic bacteria. Among them, prolyl tripeptidyl aminopeptidase from Porphylomonas gingivals and prolyl aminopeptidase from Serratia marcescens were crystallized. The complex structures of those enzymes and inhibitors were clarified in X-ray crystallography. Aminopeptidase N, which has wide specificity for amino acids, was distributed in the pathogens. The crystal structure of the aminopeptidase N elucidated the reasons for its wide substrate specificity but inertness to the X-Pro bond. It was also revealed that proline-specific peptidases and aminopeptidase N cooperatively degrade collagen for the uptake of amino acids as nutrition when these bacteria infect cells. Second, we applied enzymes from microorganisms to diagnostic analyses. We found a series of creatinine-metabolizing enzymes in Pseudomonas putida. Creatininase, creatinase, and sarcosine oxidase were coupled and have been developed for a diagnostic analysis kit that examines renal function. The structures of the native and the Mn2+-activated creatininases were determined in X-ray crystallography. Based on the structure, the activated enzyme was used for an improved assay kit. The structure of D-3-hydroxybutyrate dehydrogenase from Pseudomonas fragi was also clarified in crystallography. The enzyme is useful for diagnostic analysis of diabetes mellitus while monitoring ketone bodies.
Yoshimoto
Tadashi
T
Department of Molecular Medicinal Sciences, Division of Biotechnology, Nagasaki University, Japan. yosimoto@nagasaki-u.ac.jp
D000581:Amidohydrolases; D000626:Aminopeptidases; D001419:Bacteria / Q000201:enzymology* / Q000472:pathogenicity; D001426:Bacterial Proteins; D018826:CD13 Antigens; D018360:Crystallography, X-Ray; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; D006801:Humans; D010447:Peptide Hydrolases / Q000737:chemistry* / Q000502:physiology* / Q000627:therapeutic use; D011392:Proline / Q000378:metabolism; D011487:Protein Conformation; D011933:Reagent Kits, Diagnostic; D012697:Serine Endopeptidases; D013379:Substrate Specificity
D001426:Bacterial Proteins; D011933:Reagent Kits, Diagnostic; D011392:Proline; D010447:Peptide Hydrolases; D000626:Aminopeptidases; D018826:CD13 Antigens; C022450:prolyl aminopeptidase; D004152:Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; C118449:PtpA protein, Porphyromonas gingivalis; D012697:Serine Endopeptidases; D000581:Amidohydrolases; C019946:creatininase