Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
2009-9-28
pubmed:abstractText
An esterase (CpEst) showing high specific activities on tributyrin and short chain vinyl esters was obtained from Carica papaya latex after an extraction step with zwitterionic detergent and sonication, followed by gel filtration chromatography. Although the protein could not be purified to complete homogeneity due to its presence in high molecular mass aggregates, a major protein band with an apparent molecular mass of 41 kDa was obtained by SDS-PAGE. This material was digested with trypsin and the amino acid sequences of the tryptic peptides were determined by LC/ESI/MS/MS. These sequences were used to identify a partial cDNA (679 bp) from expressed sequence tags (ESTs) of C. papaya. Based upon EST sequences, a full-length gene was identified in the genome of C. papaya, with an open reading frame of 1029 bp encoding a protein of 343 amino acid residues, with a theoretical molecular mass of 38 kDa. From sequence analysis, CpEst was identified as a GDSL-motif carboxylester hydrolase belonging to the SGNH protein family and four potential N-glycosylation sites were identified. The putative catalytic triad was localised (Ser(35)-Asp(307)-His(310)) with the nucleophile serine being part of the GDSL-motif. A 3D-model of CpEst was built from known X-ray structures and sequence alignments and the catalytic triad was found to be exposed at the surface of the molecule, thus confirming the results of CpEst inhibition by tetrahydrolipstatin suggesting a direct accessibility of the inhibitor to the active site.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:volume
1791
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1048-56
pubmed:meshHeading
pubmed-meshheading:19555778-Amino Acid Motifs, pubmed-meshheading:19555778-Amino Acid Sequence, pubmed-meshheading:19555778-Carica, pubmed-meshheading:19555778-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:19555778-Esterases, pubmed-meshheading:19555778-Hydrogen-Ion Concentration, pubmed-meshheading:19555778-Lactones, pubmed-meshheading:19555778-Latex, pubmed-meshheading:19555778-Lipase, pubmed-meshheading:19555778-Lipolysis, pubmed-meshheading:19555778-Mass Spectrometry, pubmed-meshheading:19555778-Models, Molecular, pubmed-meshheading:19555778-Molecular Sequence Data, pubmed-meshheading:19555778-Open Reading Frames, pubmed-meshheading:19555778-Phylogeny, pubmed-meshheading:19555778-Sequence Alignment, pubmed-meshheading:19555778-Sequence Analysis, Protein, pubmed-meshheading:19555778-Solubility, pubmed-meshheading:19555778-Substrate Specificity
pubmed:year
2009
pubmed:articleTitle
Identification and biochemical characterization of a GDSL-motif carboxylester hydrolase from Carica papaya latex.
pubmed:affiliation
CNRS, Aix-Marseille Université, Enzymologie Interfaciale et Physiologie de la Lipolyse, Marseille, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't