Enzymatic degradation mechanism of a solution-grown poly[(R)-3-hydroxybutyrate] single crystal with an extracellular polyhydroxybutyrate depolymerase purified from Alcaligenes faecalis T1
نویسندگان
چکیده
We report the enzymatic degradation mechanism of a solution-grown poly[(R)-3-hydroxybutyrate] (P(3HB)) single crystal with an extracellular polyhydroxybutyrate depolymerase purified from Alcaligenes faecalis T1 (PhaZAfa). The P(3HB) single crystals adsorbed on highly ordered pyrolytic graphite were incubated with a wild-type or a hydrolytic-activity-disrupted mutant of PhaZAfa, and morphological changes of the single crystal before and after the incubation was observed by atomic force microscopy. We have concluded that P(3HB) single crystal has straight degradation pathway parallel to the long axis of crystal, and that PhaZAfa efficiently degrades P(3HB) polymer chain around the straight degradation pathway via three steps: adsorption, disturbance, and hydrolysis.
منابع مشابه
Cloning, nucleotide sequence, and expression in Escherichia coli of the gene for poly(3-hydroxybutyrate) depolymerase from Alcaligenes faecalis.
The extracellular poly(3-hydroxybutyrate) depolymerase gene from Alcaligenes faecalis T1 was cloned into Escherichia coli DH1 by using the plasmid pUC8. An A. faecalis T1 genomic library was prepared in E. coli from a partial Sau3AI digest and screened with antibody against the depolymerase. Of the 29 antibody-positive clones, 1 (pDP14), containing about 4 kilobase pairs of A. faecalis T1 DNA, ...
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