title: [Purification, characterization and application of ε-poly-L. lysine- degrading enzyme from Streptomyces sp. M-Z18 ].
abstract: [OBJECTIVE] The ε-poly-L-lysine-degrading enzyme (Pld) derived from Streptomyces sp. M-Z18 was purified and characterized. Furthermore, Pld was used to produce the low polymerization of ε-poly-L-lysine (ε-PL). [METHODS] Pld was purified to electrophoretical homogeneity through HiTrapTM Butyl HP hydrophobic chromatography after pretreated by ultrasonic and NaSCN dissolving. Subsequently, enzymatic characteristics, kinetic parameters and the time profile of ε-PL degradation by the purified Pld were studied. Meanwhile, we examined the effect of ε-PL with different degrees of polymerization on the minimal inhibitory concentration of bacteria and fungi. [RESULTS] Pld was purified to homogeneity with a final fold of 80.4 and an overall yield of 59.3%. The optimal temperature and pH for the purified Pld were 370C and 7. 0, respectively. Moreover, the Km with L-lysyl-p-nitroanilide as substrate was calculated to be 0. 621 mmol/L, and the Vmax was 701. 16 nmol/min.mg. Pld was stable in the range of pH 7. 0 - 10. 0, and temperature up to 500 C, respectively. Time profile of ε-PL degradation by the purified Pld indicated that Pld catalyzed endo-type degradation of ε- PL. The experiments of minimal inhibitory showed that ε-PL with high degree of polymerization (30 - 35) had a superior antibacterial effect on bacteria and the low degree of polymerization ε-PL (8 -20) had a better antibacterial effect on yeasts. However, ε-PL with various degrees of polymerization had a poor antibacterial effect on mould. [ CONCLUSION] The present result showed that an endo-type Pld from ε-PL-producing strain was purified. Meanwhile, it is proved that ε-PL with different degrees of polymerization have exhibited significant different antibacterial effects on microorganism.
authors.forename: Qingrui
authors.initials: Q
authors.lastname: Liu
authors.forename: Xusheng
authors.initials: X
authors.lastname: Chen
authors.forename: Xin
authors.initials: X
authors.lastname: Zeng
authors.forename: Dai
authors.initials: D
authors.lastname: Han
authors.forename: Zhonggui
authors.initials: Z
authors.lastname: Mao
mesh_terms: D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D004795:Enzyme Stability; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D011107:Polylysine / Q000737:chemistry / Q000378:metabolism*; D058105:Polymerization; D013302:Streptomyces / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics / Q000378:metabolism; D013696:Temperature
chemical_list: D001426:Bacterial Proteins; D011107:Polylysine