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FKBP‐like catalysis of peptidyl‐prolyl bond isomerization by micelles and membranes

FKBP‐like catalysis of peptidyl‐prolyl bond isomerization by micelles and membranes 10.1002/(SICI)1097-0282(199707)42:1<49::AID-BIP5>3.3.CO;2-P Under physiological conditions, peptidyl‐prolyl cis/trans isomerases catalyze powerfully the cis/trans isomerization of the ‐Xaa‐Pro‐ bond (Xaa: natural amino acids) in oligopeptides and proteins (PPIases; EC 5.2.1.8). However, incorporation of proline containing tetrapeptide‐4‐nitroanilides in micelles and phospholipid vesicles also leads to increased rates of this unimolecular conformational interconversion. The isomerization rate was dependent on the detergent and vesicle concentration, respectively. The observed rate constants fit the pseudophase model of micellar catalysis allowing the calculation of micellar turnover numbers (kcismic) and dissociation constants (KCmic). Comparing kcismic values to the rate constants of the uncatalyzed cis to trans isomerization, an acceleration factor of about 20‐fold was obtained for Suc‐Ala‐Phe‐Pro‐Phe‐4‐nitroanilide (Suc: succinyl) bound to zwitterionic SB12 (N‐dodecyl‐N,N‐dimethylammonium‐3‐propanesulfonate) micelles. In addition, a marked increase in the population of the trans conformer relative to cis was noted for all investigated combinations of peptides and detergents. In a series of tetrapeptides, Suc‐Ala‐Xaa‐Pro‐Phe‐4‐nitroanilide kcismic/KCmic as well as kcismic values are linearly correlated with the high performance liquid chromatography capacity factor R′ describing the hydrophobicity of the amino acid Xaa. The same correlation can describe quantitatively the dependency of kcar/Km on substrate hydrophobicity for the FKBP12‐catalyzed isomerization. Despite the great differences in catalytic power, these results confirm the suspicion that micelles and FKBP12 may share a common component in the catalytic mechanism of peptidyl‐prolyl bond isomerization. © 1997 John Wiley & Sons, Inc. Biopoly 42: 49–60, 1997 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Biopolymers Wiley

FKBP‐like catalysis of peptidyl‐prolyl bond isomerization by micelles and membranes

Biopolymers , Volume 42 (1) – Jul 1, 1997

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References (60)

Publisher
Wiley
Copyright
Copyright © 1997 John Wiley & Sons, Inc.
ISSN
0006-3525
eISSN
1097-0282
DOI
10.1002/(SICI)1097-0282(199707)42:1<49::AID-BIP5>3.0.CO;2-1
Publisher site
See Article on Publisher Site

Abstract

10.1002/(SICI)1097-0282(199707)42:1<49::AID-BIP5>3.3.CO;2-P Under physiological conditions, peptidyl‐prolyl cis/trans isomerases catalyze powerfully the cis/trans isomerization of the ‐Xaa‐Pro‐ bond (Xaa: natural amino acids) in oligopeptides and proteins (PPIases; EC 5.2.1.8). However, incorporation of proline containing tetrapeptide‐4‐nitroanilides in micelles and phospholipid vesicles also leads to increased rates of this unimolecular conformational interconversion. The isomerization rate was dependent on the detergent and vesicle concentration, respectively. The observed rate constants fit the pseudophase model of micellar catalysis allowing the calculation of micellar turnover numbers (kcismic) and dissociation constants (KCmic). Comparing kcismic values to the rate constants of the uncatalyzed cis to trans isomerization, an acceleration factor of about 20‐fold was obtained for Suc‐Ala‐Phe‐Pro‐Phe‐4‐nitroanilide (Suc: succinyl) bound to zwitterionic SB12 (N‐dodecyl‐N,N‐dimethylammonium‐3‐propanesulfonate) micelles. In addition, a marked increase in the population of the trans conformer relative to cis was noted for all investigated combinations of peptides and detergents. In a series of tetrapeptides, Suc‐Ala‐Xaa‐Pro‐Phe‐4‐nitroanilide kcismic/KCmic as well as kcismic values are linearly correlated with the high performance liquid chromatography capacity factor R′ describing the hydrophobicity of the amino acid Xaa. The same correlation can describe quantitatively the dependency of kcar/Km on substrate hydrophobicity for the FKBP12‐catalyzed isomerization. Despite the great differences in catalytic power, these results confirm the suspicion that micelles and FKBP12 may share a common component in the catalytic mechanism of peptidyl‐prolyl bond isomerization. © 1997 John Wiley & Sons, Inc. Biopoly 42: 49–60, 1997

Journal

BiopolymersWiley

Published: Jul 1, 1997

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