Open AccessX‐ray diffraction study of the interaction between carboxypeptidase A and ( S )‐(+)‐1‐amino‐2‐phenylethyl phosphonic acid
Author(s) -
MANGANI Stefano,
CARLONI Paolo,
ORIOLI Pierluigi
Publication year - 1992
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1992.tb19843.x
Subject(s) - crystallography , carboxypeptidase , x ray , chemistry , diffraction , carboxypeptidase a , stereochemistry , biochemistry , physics , optics , enzyme
The structure of the carboxypeptidase A complex with the inhibitor ( S )‐(+)‐1‐amino‐2‐phenylethylphosphonic acid has been determined at 0.23 nm resolution. The Δ F map shows electrondensity peaks both in the S 1 and S' 1 sites, where the inhibitor molecule can be modeled in two different orientations with approximate 50% occupancy. In the proposed model, the phosphonate group binds to the zinc in a monodentate fashion. Other anchoring groups for the inhibitor molecule are Arg127 (hydrogen bonds with the phosphonate oxygen atoms) and Glu270 (hydrogen bond with the amino group in one of the two orientations). A recent spectroscopic investigation of the complex between cobalt(II) carboxypeptidase A and ( S )‐(+)‐1‐amino‐2‐phenylethylphosphonic acid is essentially in agreement with our results.