The characterization of a cyclophilin-type peptidyl prolyl cis-trans-isomerase from the endoplasmic-reticulum lumen.
A luminally located peptidyl prolyl cis-trans-isomerase (PPI) has been purified from bovine liver microsomes. It has a molecular mass of 20.6 kDa, and N-terminal sequencing demonstrates strong sequence similarity to the sequences of the cyclophilin B family. The enzyme catalyses the isomerization of the standard proline-containing peptide N-succinyl-Ala-Ala-Pro-Phe p-nitroanilide, as well as the refolding of RNAase T1. Kinetic properties, substrate-specificity data and inhibition by cyclosporin A indicate that it is a cyclophilin-type PPI, consistent with the amino-acid-sequence results.
Research School of Biosciences, Biological Laboratory, University of Kent, Canterbury, U.K.
S
S
Bose
M
M
Mücke
R B
RB
Freedman
D000591:Amino Acid Isomerases / Q000037:antagonists & inhibitors / Q000276:immunology / Q000302:isolation & purification*; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D002352:Carrier Proteins / Q000037:antagonists & inhibitors / Q000276:immunology / Q000302:isolation & purification*; D002417:Cattle; D016572:Cyclosporine / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000201:enzymology*; D007700:Kinetics; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D011487:Protein Conformation; D013379:Substrate Specificity
D002352:Carrier Proteins; D016572:Cyclosporine; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase