Evidence for lytic transglycosylase and β-N-acetylglucosaminidase activities located at the polyhydroxyalkanoates (PHAs) granules of Thermus thermophilus HB8.

摘要: The thermophilic bacterium Thermus thermophilus HB8 accumulates polyhydroxyalkanoates (PHAs) as intracellular granules used by cells carbon and energy storage compounds. PHAs were isolated from grown in sodium gluconate (1.5 % w/v) source. Lytic activities are strongly associated act to the proved with various methods. Specialized lytic trasglycosylases (LTGs) muramidases capable of locally degrading peptidoglycan (PG) meshwork Gram negative bacteria. These enzymes cleave β-1,4-glycosidic linkages between N-acetylmuramic acid (MurNAc) N-acetylglucosamine (GlcNAc) residues PG. Lysozyme-like activity/-ies detected using lysoplate assay. Chitinolytic activity/-ies, N-acetyl glucosaminidases (NAG) (E.C.3.2.1.5.52) hydrolyzing synthetic substrate p-nitrophenyl-N-acetyl-β-D-glucosaminide (pNP-GlcNAc) releasing pNP GlcNAc. Using zymogram analysis two abundant LTGs revealed cell wall Micrococcus lysodeikticus or purified PG incorporated natural substrates, SDS-PAGE then renaturation. proteins corresponded a Coomassie-stained gel molecular mass 110 32 kDa respectively, analyzed MALDI-MS (Matrix-assisted laser desorption/ionization-Mass Spectrometry). protein was identified an S-layer domain-containing [gi|336233805], while similar hypothetical VDG1235_2196 (gi/254443957). Overall, localization hydrolases appears be involved their biogenesis membranes, probably promoting septal splitting daughter separation.