The cis/trans interconversion of the calcium regulating hormone calcitonin is catalyzed by cyclophilin.
The cytosolic peptidyl-prolyl cis/trans isomerase cyclophilin from pig kidney can accelerate catalytically the cis/trans isomerization of prolyl peptide bonds. One- and two-dimensional 1H NMR spectroscopy was used to prove that the polypeptide hormone calcitonin is a substrate for cyclophilin. Isomerization of only one of the two prolyl peptide bonds is catalyzed significantly. The efficiency of catalysis was calculated by lineshape analysis and NOESY spectroscopy. Cyclosporin A completely blocks the effect of the enzyme on the conformational dynamics of the polypeptide.
Max-Planck-Gesellschaft, Arbeitsgruppe Enzymologie der Peptidbindung, Halle/Saale, Germany.
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Drakenberg
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Wikström
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Forsén
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Fischer
D000591:Amino Acid Isomerases / Q000494:pharmacology*; D000595:Amino Acid Sequence; D002118:Calcium / Q000737:chemistry / Q000378:metabolism*; D002352:Carrier Proteins / Q000494:pharmacology*; D003524:Cyclosporins / Q000378:metabolism; D006801:Humans; D007536:Isomerism; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D019696:Peptidylprolyl Isomerase; D011487:Protein Conformation; D013816:Thermodynamics
D002352:Carrier Proteins; D003524:Cyclosporins; D000591:Amino Acid Isomerases; D019696:Peptidylprolyl Isomerase; D002118:Calcium