7GCH

STRUCTURE OF CHYMOTRYPSIN-*TRIFLUOROMETHYL KETONE INHIBITOR COMPLEXES. COMPARISON OF SLOWLY AND RAPIDLY EQUILIBRATING INHIBITORS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structure of chymotrypsin-trifluoromethyl ketone inhibitor complexes: comparison of slowly and rapidly equilibrating inhibitors.

Brady, K.Wei, A.Z.Ringe, D.Abeles, R.H.

(1990) Biochemistry 29: 7600-7607

  • Primary Citation of Related Structures:  
  • Also Cited By: 3GCH

  • PubMed Abstract: 
  • The peptidyl trifluoromethyl ketones Ac-Phe-CF3 (1) and Ac-Leu-Phe-CF3 (2) are inhibitors of chymotrypsin. They differ in Ki (20 and 2 microM, respectively) as well as in their kinetics of association with chymotrypsin in that 1 is rapidly equilibrat ...

    The peptidyl trifluoromethyl ketones Ac-Phe-CF3 (1) and Ac-Leu-Phe-CF3 (2) are inhibitors of chymotrypsin. They differ in Ki (20 and 2 microM, respectively) as well as in their kinetics of association with chymotrypsin in that 1 is rapidly equilibrating, with an association rate too fast to be observed by steady-state techniques, while 2 is "slow binding", as defined by Morrison and Walsh [Morrison, J. F., & Walsh, C. T. (1988) Adv. Enzymol. Relat. Areas Mol. Biol. 61, 202], with a second-order association rate constant of 750 M-1 s-1 at pH 7.0 [Imperiali, B., & Abeles, R. (1986) Biochemistry 25, 3760]. The crystallographic structures of the complexes of gamma-chymotrypsin with inhibitors 1 and 2 have been determined in order to establish whether structural or conformational differences can be found which account for different kinetic and thermodynamic properties of the two inhibitors. In both complexes, the active-site Ser 195 hydroxyl forms a covalent hemiketal adduct with the trifluoromethyl ketone moiety of the inhibitor. In both complexes, the trifluoromethyl group is partially immobilized, but differences are observed in the degree of interaction of fluorine atoms with the active-site His 57 imidazole ring, with amide nitrogen NH 193, and with other portions of the inhibitor molecule. The enhanced potency of Ac-Leu-Phe-CF3 relative to Ac-Phe-CF3 is accounted for by van der Waals interactions of the leucine side chain of the inhibitor with His 57 and Ile 99 side chains and by a hydrogen bond of the acetyl terminus with amide NH 216 of the enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)


    Related Citations: 
    • Photolysis and Deacylation of Inhibited Chymotrypsin
      Stoddard, B.L.,Bruhnke, J.,Koenig, P.,Porter, N.,Ringe, D.,Petsko, G.A.
      (1990) Biochemistry 29: 8042
    • Structure and Activity of Two Photoreversible Cinnamates Bound to Chymotrypsin
      Stoddard, B.L.,Bruhnke, J.,Porter, N.,Ringe, D.,Petsko, G.A.
      (1990) Biochemistry 29: 4871
    • Inhibition of Chymotrypsin by Peptidyl Trifluoromethy Ketones. Determinants of Slow-Binding Kinetics
      Brady, K.,Abeles, R.H.
      (1990) Biochemistry 29: 7608
    • Ph Dependence of the Inhibition of Chymotrypsin by a Peptidyl Trifluoromethyl Ketone
      Liang, K.Brady.T.-C.,Abeles, R.H.
      (1989) Biochemistry 28: 9066


    Organizational Affiliation

    Department of Toxicology, Harvard School of Public Health, Boston, Massachusetts 02115.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GAMMA-CHYMOTRYPSIN A
E
13Bos taurusMutation(s): 0 
EC: 3.4.21.1
Find proteins for P00766 (Bos taurus)
Go to UniProtKB:  P00766
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
GAMMA-CHYMOTRYPSIN A
F
131Bos taurusMutation(s): 0 
EC: 3.4.21.1
Find proteins for P00766 (Bos taurus)
Go to UniProtKB:  P00766
Entity ID: 3
MoleculeChainsSequence LengthOrganismDetails
GAMMA-CHYMOTRYPSIN A
G
97Bos taurusMutation(s): 0 
EC: 3.4.21.1
Find proteins for P00766 (Bos taurus)
Go to UniProtKB:  P00766
Small Molecules
Ligands 1 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
LPF
Query on LPF

Download SDF File 
Download CCD File 
G
1,1,1-TRIFLUORO-3-((N-ACETYL)-L-LEUCYLAMIDO)-4-PHENYL-BUTAN-2-ONE(N-ACETYL-L-LEUCYL-L-PHENYLALANYL TRIFLUOROMETHYL KETONE)
C18 H23 F3 N2 O3
MZNXJCZDQRNGRC-GJZGRUSLSA-N
 Ligand Interaction
External Ligand Annotations 
IDBinding Affinity (Sequence Identity %)
LPFKi: 2000 nM PDBBIND
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.8 Å
  • Space Group: P 42 21 2
Unit Cell:
Length (Å)Angle (°)
a = 69.300α = 90.00
b = 69.300β = 90.00
c = 97.600γ = 90.00
Software Package:
Software NamePurpose
PROLSQrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1990-10-15
    Type: Initial release
  • Version 1.1: 2008-03-25
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Derived calculations, Version format compliance