Academic Thesis

Basic information

Name Koga Yuuichi
Belonging department
Occupation name
researchmap researcher code 5000076449
researchmap agency Okayama University of Science

Title

Requirement of lid2 for interfacial activation of a family I.3 lipase with unique two lid structures.

Bibliography Type

 

Author

Maria Cheng
Clement Angkawidjaja
Yuichi Koga
Shigenori Kanaya

Summary

A family I.3 lipase from Pseudomonas sp. MIS38 (PML) is characterized by the presence of two lids (lid1 and lid2) that greatly change conformation upon substrate binding. While lid1 represents the commonly known lid in lipases, lid2 is unique to PML and other family I.3 lipases. To clarify the role of lid2 in PML, a lid2 deletion mutant (ΔL2-PML) was constructed by deleting residues 35-64 of PML. ΔL2-PML requires calcium ions for both lipase and esterase activities as does PML, suggesting that it exhibits activity only when lid1 is fully open and anchored by the catalytically essential calcium ion, as does PML. However, when the enzymatic activity was determined using triacetin, the activity of PML exponentially increased as the substrate concentration reached and increased beyond the critical micellar concentration, while that of ΔL2-PML did not. These results indicate that PML undergoes interfacial activation, while ΔL2-PML does not. The activities of ΔL2-PML for long-chain triglycerides significantly decreased while its activity for fatty acid ethyl esters increased, compared with those of PML. Comparison of the tertiary models of ΔL2-PML in a closed and open conformation, which are optimized by molecular dynamics simulation, with the crystal structures of PML suggests that the hydrophobic surface area provided by lid1 and lid2 in an open conformation is considerably decreased by the deletion of lid2. We propose that the hydrophobic surface area provided by these lids is necessary to hold the micellar substrates firmly to the active site and therefore lid2 is required for interfacial activation of PML.

Magazine(name)

The FEBS journal

Publisher

WILEY-BLACKWELL

Volume

279

Number Of Pages

19

StartingPage

3727

EndingPage

3737

Date of Issue

2012-10

Referee

Exist

Invited

Not exist

Language

English

Thesis Type

Research papers (academic journals)

ISSN

 

DOI

10.1111/j.1742-4658.2012.08734.x

NAID

 

PMID

 

J-GLOBAL ID

 

arXiv ID

 

ORCID Put Code

 

DBLP ID