title: Characterization and inhibitor discovery of one novel malonyl-CoA: acyl carrier protein transacylase (MCAT) from Helicobacter pylori.
abstract: Type II fatty acid synthesis (FAS II) is an essential process for bacteria survival, and malonyl-CoA:acyl carrier protein transacylase (MCAT) is a key enzyme in FAS II pathway, which is responsible for transferring the malonyl group from malonyl-CoA to the holo-ACP by forming malonyl-ACP. In this work, we described the cloning, characterization and enzymatic inhibition of a new MCAT from Helicobacter pylori strain SS1 (HpMCAT), and the gene sequence of HpfabD was deposited in the GenBank database (Accession No. AY738332 ). Enzymatic characterization of HpMCAT showed that the K(m) value for malonyl-CoA was 21.01+/-2.3 microM, and the thermal- and guanidinium hydrochloride-induced unfolding processes for HpMCAT were quantitatively investigated by circular dichroism spectral analyses. Moreover, a natural product, corytuberine, was discovered to demonstrate inhibitory activity against HpMCAT with IC(50) value at 33.1+/-3.29 microM. Further enzymatic assay results indicated that corytuberine inhibits HpMCAT in an uncompetitive manner. To our knowledge, this is the firstly reported MCAT inhibitor to date. This current work is hoped to supply useful information for better understanding the MCAT features of H. pylori strain, and corytuberine might be used as a potential lead compound in the discovery of the antibacterial agents using HpMCAT as target.
authors.affiliation: Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Graduate School of the Chinese Academy of Sciences, Shanghai 201203, China.
authors.forename: Weizhi
authors.initials: W
authors.lastname: Liu
authors.forename: Cong
authors.initials: C
authors.lastname: Han
authors.forename: Lihong
authors.initials: L
authors.lastname: Hu
authors.forename: Kaixian
authors.initials: K
authors.lastname: Chen
authors.forename: Xu
authors.initials: X
authors.lastname: Shen
authors.forename: Hualiang
authors.initials: H
authors.lastname: Jiang
mesh_terms: D051080:Acyl-Carrier Protein S-Malonyltransferase / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000595:Amino Acid Sequence; D001060:Aporphines / Q000378:metabolism; D001426:Bacterial Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004795:Enzyme Stability; D005227:Fatty Acids / Q000096:biosynthesis; D016480:Helicobacter pylori / Q000201:enzymology*; D008969:Molecular Sequence Data; D015394:Molecular Structure; D011489:Protein Denaturation; D016415:Sequence Alignment
chemical_list: D001060:Aporphines; D001426:Bacterial Proteins; D005227:Fatty Acids; C013896:corytuberine; D051080:Acyl-Carrier Protein S-Malonyltransferase