Molecular characterization of a cyclosporin A-insensitive cyclophilin from the parasitic nematode Brugia malayi.
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.
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New England Biolabs, Beverly, Massachusetts 01915, USA.
Landry
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Wilson
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Carlow
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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
D002352:Carrier Proteins; D018076:DNA, Complementary; D011994:Recombinant Proteins; D016572:Cyclosporine; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase