ISSN:
0887-3585
Keywords:
calmodulin
;
purothionin
;
CD and fluorescence spectroscopy
;
calmodulin-binding peptides
;
modeling
;
calmodulin-peptide interaction
;
computer graphics
;
Chemistry
;
Biochemistry and Biotechnology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
CD and fluorescence spectroscopic measurements show that calmodulin (CaM) binds to purothionins (alpha;1-purothionin: α1-PT; β-purothionin: β-PT) in 1:1 stoichiometry with an affinity similar to that exhibited with the tightest binding CaM-binding peptides. Using the available crystal structures of CaM and α1-PT, a model has been built for the interaction of CaM and α1-PT and subjected to potential energy minimization. In the model, there is a bend in the central helix of CaM similar to that suggested by Persechini and Kretsinger (J. Card. Pharm. 12:501-512, 1988). α1-PT fits snugly into the cavity formed by the bent CaM molecule with each of its two helices making apolar interactions with each of the two hydrophobic clefts situated at the terminal domains of CaM. The complex is further stabilized by numerous polar and electrostatic interactions on the rims of the clefts. Our model is compared with two other similar models previously re-ported for the CaM complexes with other helical peptides and generalizations about the mode of CaM binding to target proteins are made, which have wide relevance to the function of CaM. By analogy, a similar model is pre-dicted for a CaM-β-PT complex. © 1992 Wiley-Liss, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/prot.340140202
Permalink
