Báo cáo Y học: Molecular modeling of the dimeric structure of human lipoprotein lipase and functional studies of the carboxyl-terminal domain

Molecular Modeling of the Dimeric Structure of Human Lipoprotein Lipase and Functional Studies of the Carboxyl-Terminal Domain

Authors: Yoko Kobayashi, Toshiaki Nakajima, and Ituro Inoue

Field: Biochemistry / Molecular Biology

Document Content: This document presents a molecular modeling study of the dimeric structure of human lipoprotein lipase (LPL), an enzyme crucial for lipid metabolism. The study utilizes computational modeling based on crystal structures of related lipases to propose a saddle-shaped dimeric model for LPL. It investigates the roles of specific residues within the N-terminal and C-terminal domains in heparin binding, substrate recognition, and catalytic activity. The research also provides experimental evidence supporting a head-to-tail orientation for the LPL dimer, which is essential for efficient enzyme function. Through site-directed mutagenesis and analysis of mutant protein activities, the study elucidates the structure-function relationships of the LPL C-terminal domain.

Detailed Table of Contents:

• Introduction to Lipoprotein Lipase (LPL)
• Molecular Modeling of Dimeric LPL
• Functional Studies of the Carboxyl-Terminal Domain
• Site-Directed Mutagenesis and Expression of LPL in Cultured Cells
• In Vitro Translation of the LPL C-Terminal Domain
• Determination of LPL Heparin Affinity
• LPL Concentration Determination
• Assay of Lipase and Esterase Activities
• Western Blotting
• Construction of the LPL Model Structure
• Model Structure of Human LPL
• Impact of C-Terminal Substitutions on Heparin Binding to Full-Length LPL
• Catalytic Activities with Long- and Short-Chain Fatty Acid Substrates
• Conformational Changes in the LPL Mutant Models
• Recovery of Lipase Activity after Cotransfection of S132T and WWW Mutants
• Discussion
• Acknowledgements
• References