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Mutations in the “lid” region affect chain length specificity and thermostability of a Pseudomonas fragi lipase
Author(s) -
Santarossa Gianluca,
Lafranconi Pietro Gatti,
Alquati Claudia,
DeGioia Luca,
Alberghina Lilia,
Fantucci Piercarlo,
Lotti Marina
Publication year - 2005
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/j.febslet.2005.03.037
Subject(s) - thermostability , lipase , serine , biochemistry , glycine , chemistry , enzyme , residue (chemistry) , pseudomonas , stereochemistry , amino acid , biology , genetics , bacteria
The cold‐adapted Pseudomonas fragi lipase (PFL) displays highest activity on short‐chain triglyceride substrates and is rapidly inactivated at moderate temperature. Sequence and structure comparison with homologous lipases endowed with different substrate specificity and stability, pointed to three polar residues in the lid region, that were replaced with the amino acids conserved at equivalent positions in the reference lipases. Substitutions at residues T137 and T138 modified the lipase chain‐length preference profile, increasing the relative activity towards C8 substrates. Moreover, mutations conferred to PFL higher temperature stability. On the other hand, replacement of the serine at position 141 by glycine destabilized the protein.