Levin I

References (3)

Title : Structure of Human GIVD Cytosolic Phospholipase A2 Reveals Insights into Substrate Recognition - Wang_2016_J.Mol.Biol_428_2769
Author(s) : Wang H , Klein MG , Snell G , Lane W , Zou H , Levin I , Li K , Sang BC
Ref : Journal of Molecular Biology , 428 :2769 , 2016
Abstract : Cytosolic phospholipases A2 (cPLA2s) consist of a family of calcium-sensitive enzymes that function to generate lipid second messengers through hydrolysis of membrane-associated glycerophospholipids. The GIVD cPLA2 (cPLA2delta) is a potential drug target for developing a selective therapeutic agent for the treatment of psoriasis. Here, we present two X-ray structures of human cPLA2delta, capturing an apo state, and in complex with a substrate-like inhibitor. Comparison of the apo and inhibitor-bound structures reveals conformational changes in a flexible cap that allows the substrate to access the relatively buried active site, providing new insight into the mechanism for substrate recognition. The cPLA2delta structure reveals an unexpected second C2 domain that was previously unrecognized from sequence alignments, placing cPLA2delta into the class of membrane-associated proteins that contain a tandem pair of C2 domains. Furthermore, our structures elucidate novel inter-domain interactions and define three potential calcium-binding sites that are likely important for regulation and activation of enzymatic activity. These findings provide novel insights into the molecular mechanisms governing cPLA2's function in signal transduction.
ESTHER : Wang_2016_J.Mol.Biol_428_2769
PubMedSearch : Wang_2016_J.Mol.Biol_428_2769
PubMedID: 27220631

Title : Crystal structure of an alpha\/beta serine hydrolase (YDR428C) from Saccharomyces cerevisiae at 1.85 A resolution -
Author(s) : Arndt JW , Schwarzenbacher R , Page R , Abdubek P , Ambing E , Biorac T , Canaves JM , Chiu HJ , Dai X , Deacon AM , DiDonato M , Elsliger MA , Godzik A , Grittini C , Grzechnik SK , Hale J , Hampton E , Han GW , Haugen J , Hornsby M , Klock HE , Koesema E , Kreusch A , Kuhn P , Jaroszewski L , Lesley SA , Levin I , McMullan D , McPhillips TM , Miller MD , Morse A , Moy K , Nigoghossian E , Ouyang J , Peti WS , Quijano K , Reyes R , Sims E , Spraggon G , Stevens RC , van den Bedem H , Velasquez J , Vincent J , von Delft F , Wang X , West B , White A , Wolf G , Xu Q , Zagnitko O , Hodgson KO , Wooley J , Wilson IA
Ref : Proteins , 58 :755 , 2005
PubMedID: 15624212
Gene_locus related to this paper: yeast-YDR428C

Title : Structural and kinetic analysis of the substrate specificity of human fibroblast activation protein alpha - Aertgeerts_2005_J.Biol.Chem_280_19441
Author(s) : Aertgeerts K , Levin I , Shi L , Snell GP , Jennings A , Prasad GS , Zhang Y , Kraus ML , Salakian S , Sridhar V , Wijnands R , Tennant MG
Ref : Journal of Biological Chemistry , 280 :19441 , 2005
Abstract : Fibroblast activation protein alpha (FAPalpha) is highly expressed in epithelial cancers and has been implicated in extracellular matrix remodeling, tumor growth, and metastasis. We present the first high resolution structure for the apoenzyme as well as kinetic data toward small dipeptide substrates. FAPalpha exhibits a dipeptidyl peptidase IV (DPPIV)-like fold, featuring an alpha/beta-hydrolase domain and an eight-bladed beta-propeller domain. Known DPPIV dipeptides are cleaved by FAPalpha with an approximately 100-fold decrease in catalytic efficiency compared with DPPIV. Moreover, FAPalpha, but not DPPIV, possesses endopeptidase activity toward N-terminal benzyloxycarbonyl (Z)-blocked peptides. Comparison of the crystal structures of FAPalpha and DPPIV revealed one major difference in the vicinity of the Glu motif (Glu(203)-Glu(204) for FAPalpha; Glu(205)-Glu(206) for DPPIV) within the active site of the enzyme. Ala(657) in FAPalpha, instead of Asp(663) as in DP-PIV, reduces the acidity in this pocket, and this change could explain the lower affinity for N-terminal amines by FAPalpha. This hypothesis was tested by kinetic analysis of the mutant FAPalpha/A657D, which shows on average an approximately 60-fold increase in the catalytic efficiency, as measured by k(cat)/K(m), for the cleavage of dipeptide substrates. Furthermore, the catalytic efficiency of the mutant is reduced by approximately 350-fold for cleavage of Z-Gly-Pro-7-amino-4-methylcoumarin. Our data provide a clear understanding of the molecular determinants responsible for the substrate specificity and endopeptidase activity of FAPalpha.
ESTHER : Aertgeerts_2005_J.Biol.Chem_280_19441
PubMedSearch : Aertgeerts_2005_J.Biol.Chem_280_19441
PubMedID: 15809306
Gene_locus related to this paper: human-FAP