The crystal structure of an HSL-homolog EstE5 complex with PMSF reveals a unique configuration that inhibits the nucleophile Ser144 in catalytic triads.
The esterase/lipase family (EC 3.1.1.3/EC 3.1.1.1) represents a diverse group of hydrolases that catalyze the cleavage of ester bonds and are widely distributed in animals, plants and microorganisms. Among these enzymes, hormone-sensitive lipases, play a critical role in the regulation of rodent fat cell lipolysis and are regarded as adipose tissue-specific enzymes. Recently, we reported the structural and biological characterization of EstE5 from the metagenome library [K.H. Nam, M.Y. Kim, S.J. Kim, A. Priyadarshi, W.H. Lee, K.Y. Hwang, Structural and functional analysis of a novel EstE5 belonging to the subfamily of hormone-sensitive lipase, Biochem. Biophys. Res. Commun. 379 (2009) 553-556]. The structure of this protein revealed that it belongs to the HSL-family. Here, we report the inhibition of the activity of the HSL-homolog EstE5 protein as determined by the use of esterase/lipase inhibitors. Our results revealed that the EstE5 protein is significantly inhibited by PMSF. In addition, this is the first study to identify the crystal structures of EstE5-PMSF at 2.4 and 2.5A among the HSL-homolog structures. This structural configuration is similar to that adopted when serine proteases are inhibited by PMSF. The results presented here provide valuable information regarding the properties of the HSL-family.
Nam
Ki Hyun
KH
Division of Biotechnology, College of Life Sciences & Biotechnology, Korea University, Seoul 136-701, Republic of Korea.
Kim
Soo-Jin
SJ
Priyadarshi
Amit
A
Kim
Hyun Sook
HS
Hwang
Kwang Yeon
KY
D002384:Catalysis; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D011480:Protease Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D011487:Protein Conformation; D012694:Serine / Q000737:chemistry*; D002787:Sterol Esterase / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D014105:Tosyl Compounds / Q000737:chemistry* / Q000494:pharmacology
D011480:Protease Inhibitors; D014105:Tosyl Compounds; D012694:Serine; C003614:4-toluenesulfonyl fluoride; D002787:Sterol Esterase