Open AccessPoly(3‐hydroxybutyrate) depolymerases bind to their substrate by a C‐terminal located substrate binding site
Author(s) -
Behrends Astrid,
Klingbeil Britta,
Jendrossek Dieter
Publication year - 1996
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.1996.tb08479.x
Subject(s) - chemistry , substrate (aquarium) , cellulose , amino acid , binding site , biochemistry , bioorganic chemistry , stereochemistry , enzyme , biology , ecology
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.