title: Molecular characterization of a cyclosporin A-insensitive cyclophilin from the parasitic nematode Brugia malayi.
abstract: The cyclophilins are a family of proteins that exhibit peptidyl-prolyl cis-trans isomerase (PPIase, EC 5.2.1.8) activity and bind the immunosuppressive agent cyclosporin A (CsA) to varying degrees. We have isolated a cDNA clone encoding a novel cyclophilin from the human filarial parasite Brugia malayi. This gene possesses an N-terminal domain homologous to cyclophilins from diverse phyla (49-60% amino acid sequence identity) and a hydrophilic C-terminal domain. The cyclophilin domain was overexpressed in Escherichia coli and found to possess peptidyl-prolyl cis-trans isomerase (PPIase) activity, with a kcat/Km value of 7.9 x 10(6) M-1 s-1. A histidine residue in lieu of tryptophan in the highly conserved CsA-binding site suggests that B. malayi cyclophilin is more closely related to the cyclophilin-like proteins described recently from natural killer (NK) cells, plants, and the 40 kDa cyclophilins from mammals. In accordance with the histidine-containing CsA-binding domain, the B. malayi enzyme was relatively insensitive to inhibition by CsA, since an IC50 value of 860 nM (compared to 19 nM for human cyclophilin A) was determined.
authors.affiliation: New England Biolabs, Beverly, Massachusetts 01915, USA.
authors.forename: A P
authors.initials: AP
authors.lastname: Page
authors.forename: D
authors.initials: D
authors.lastname: Landry
authors.forename: G G
authors.initials: GG
authors.lastname: Wilson
authors.forename: C K
authors.initials: CK
authors.lastname: Carlow
mesh_terms: D000591:Amino Acid Isomerases / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015139:Blotting, Southern; D017178:Brugia malayi / Q000737:chemistry / Q000235:genetics*; D002352:Carrier Proteins / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D003001:Cloning, Molecular; D016572:Cyclosporine / Q000494:pharmacology*; D018076:DNA, Complementary; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D011994:Recombinant Proteins / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D011994:Recombinant Proteins; D016572:Cyclosporine; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase