Function of C-terminal peptides on enzymatic and interfacial adsorption properties of lipase from Gibberella zeae

Publication date: Available online 17 July 2018Source: Biochimica et Biophysica Acta (BBA) - General SubjectsAuthor(s): Fanghua Wang, Hui Zhang, Anna Czarna, Wuchong Chen, Bo Yang, Yonghua WangAbstractBackgroundThe crystal structure of lipase from Gibberella zeae (GZEL) indicates that its C-terminal extension is composed of a loop and a α-helix. This structure is unique, possibly providing novel evidence on lipase mechanisms.MethodsTwo C-terminally truncated mutants (GZEL-Δ(α-helix) and GZEL-Δ(α-helix+loop)) were constructed. The role of these secondary structure segments on enzymatic activities and interfacial binding properties of GZEL was investigated by using conventional pH-stat method and monomolecular film techniques. In addition, inactive variants (Ser144Ala) of wild-type GZEL and two truncated mutants were constructed and produced specifically for interfacial binding experiments.ResultsCompared to the wild-type GZEL, lipase and phospholipase activities were significantly decreased in the two mutants. Deletion of the α-helix had great influence on the lipase activity of GZEL, resulting in residual 7.3% activity; the additional deletion of the loop led to 8.1% lipase activity. As for the phospholipase function, residual activities of 63.0% and 35.4% were maintained for GZEL-Δ(α-helix) and GZEL-Δ(α-helix+loop), respectively. Findings obtained with monomolecular film experiments further indicated that the reduction in phospholipase activity occurred with the an...
Source: Biochimica et Biophysica Acta (BBA) General Subjects - Category: Biochemistry Source Type: research