Mutations in the "lid" region affect chain length specificity and thermostability of a Pseudomonas fragi lipase.
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.
Santarossa
Gianluca
G
Dipartimento di Biotecnologie e Bioscienze, Università degli Studi di Milano-Bicocca, Italy.
Lafranconi
Pietro Gatti
PG
Alquati
Claudia
C
DeGioia
Luca
L
Alberghina
Lilia
L
Fantucci
Piercarlo
P
Lotti
Marina
M
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001665:Binding Sites; D002210:Caprylates / Q000378:metabolism; D004795:Enzyme Stability; D006868:Hydrolysis; D007700:Kinetics; D008049:Lipase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics*; D011489:Protein Denaturation; D017434:Protein Structure, Tertiary; D044206:Pseudomonas fragi / Q000201:enzymology* / Q000235:genetics; D016415:Sequence Alignment; D013379:Substrate Specificity; D013696:Temperature; D014280:Triglycerides / Q000378:metabolism
D002210:Caprylates; D014280:Triglycerides; C003637:tricaprylin; C004565:trilaurin; D008049:Lipase; C005830:tributyrin