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B Klingbeil

Publications and source records attributed to B Klingbeil.

3 recordsLinked to original sources
PubMed1996

Poly(3-hydroxybutyrate) depolymerases bind to their substrate by a C-terminal located substrate binding site.

Binding of (i) purified wild-type poly(3-hydroxybutyrate) (PHB) depolymerase PhaZ4 of Pseudomonas lemoignei, (ii) a purified truncated form of PhaZ4, which lacked 55 C-terminal amino acids and (iii) commercial lactate dehydrogenase to aqueous suspensions of PHB, chitin or cellulose was studied. Only the wild-type PHB depolymerase was specifically able to bind to PHB granules. No other combination of protein and polymeric substrate resulted in polymer-bound protein. Similar results were obtained for other PHB depolymerases. We concluded that the C-terminal amino acids of PHB depolymerases represent a PHB-specific binding domain or at least an essential part of it.

Amino Acid Sequence↗
PubMed1996

Taxonomic identification of Streptomyces exfoliatus K10 and characterization of its poly(3-hydroxybutyrate) depolymerase gene.

The poly(3-hydroxyalkanoate) (PHA) degrading isolate K10 was identified as Streptomyces exfoliatus. This bacterium is distinguished from other PHA-degrading strains by its ability to utilize both poly(3-hydroxybutyrate) (PHB) and poly(3-hydroxyoctanoate) (PHO). A PHA depolymerase structural gene of S. exfoliatus (phaZ(Sex) was cloned, expressed and partially purified from recombinant Escherichia coli. The depolymerase was specific for PHB and did not hydrolyze PHO. This indicated the presence of at least one additional gene in S. exfoliatus which encodes a PHO depolymerase. 3-Hydroxybutyrate was identified as the only product of PHB hydrolysis. Comparison of the DNA-deduced amino acid sequence revealed high homology to the PHB depolymerase of Comamonas sp. and low to medium homologies to other PHA depolymerases. The PHB depolymerases of S. exfoliatus and Comamonas sp. represent a subgroup within the family of PHA(SCL) depolymerases. To our knowledge, the S. exfoliatus PHB depolymerase is the first briefly characterized PHA depolymerase of a Gram-positive.

Amino Acid Sequence↗