Active site titration of bovine beta-trypsin by N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester: kinetic and crystallographic analysis.
FEBS Lett
; 358(1): 53-6, 1995 Jan 16.
Article
in En
| MEDLINE
| ID: mdl-7821429
ABSTRACT
Kinetics of bovine beta-trypsin (trypsin) with the N alpha-(N,N-dimethylcarbamoyl)-alpha-aza-lysine p-nitrophenyl ester (Dmc-azaLys-ONp) was obtained at pH 6.2 and 21.0 degrees C. Dmc-azaLys-ONp shows the characteristics of an optimal active site titrant in that it (i) gives titrations in a short time, (ii) is a stable and soluble compound with a stoichiometric reaction that is easily and directly detectable, and (iii) allows titrations over a wide range of enzyme concentration. Moreover, the three-dimensional structure of the trypsin.N alpha-(N,N-dimet hylcarbamoyl)-alpha-aza-lysine acyl.enzyme adduct has been solved by X-ray crystallography at 2.0 A resolution (R = 0.145). The Dmc-azaLys moiety of the active site titrant is sited in the serine proteinase reaction center, and is covalently linked to the OG atom of the Ser195 catalytic residue.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Aza Compounds
/
Trypsin
/
Trypsin Inhibitors
/
Lysine
Limits:
Animals
Language:
En
Journal:
FEBS Lett
Year:
1995
Document type:
Article
Affiliation country:
Italy