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E-64 [1-[N-[(L-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl] amino]-4-guanidinobutane] is an irreversible inhibitor of many cysteine proteases. A papain-E-64 complex was crystallized at pH 6.3 by using the hanging drop method. Three different crystal forms grew in 3-7 days; the form chosen for structure analysis has space group P212121, with a = 42.91(4) A, b = 102.02(6) A, c = 49.73(2) A, and Z = 4. Diffraction data were measured to 2.4-A resolution, giving 9367 unique reflections. The papain structure was solved by use of the molecular replacement method, and then the inhibitor was located from a difference electron density map and fitted with the aid of a PS330 computer graphics system. The structure of the complex was refined to R = 23.3%. Our analysis shows that a covalent link is formed between the sulfur of the active-site cysteine 25 and the C-2 atom of the inhibitor. Contrary to earlier predictions, the E-64 inhibitor clearly interacts with the S subsites on the enzyme rather than the S' subsites, and papain's histidine 159 imidazole group plays a binding rather than a catalytic role in the inactivation process.
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
June 1992,
Biochemistry,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
August 1996,
FEBS letters,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
February 1997,
Nature structural biology,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
April 1990,
FEBS letters,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
May 2007,
Acta crystallographica. Section D, Biological crystallography,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
July 1981,
Journal of biochemistry,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
October 1989,
Chemical & pharmaceutical bulletin,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
March 1989,
FEBS letters,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
April 1997,
FEBS letters,
K I Varughese, and
F R Ahmed, and
P R Carey, and
S Hasnain, and
C P Huber, and
A C Storer
November 1992,
The Biochemical journal,
