22 research outputs found
CIRCULAR-DICHROISM EVIDENCE FOR A STEREOSPECIFIC COMPLEXATION REACTION IN COPPER(II) CHELATES OF POLY-ALPHA-AMINO-ACID LIGANDS
Influence of the Chain Conformation on Optical and Chemical Properties of Active Molecules Anchored to the polypeptide Matrices
Influenza della Struttura e della RigiditĂ Conformazionale di Matrici Polipeptidiche sulla ReattivitĂ in Soluzione di Molecole Ancorate
Struttura e ProprietĂ delle Basi di Schiff del Piridossale con Polipeptidi Basici e dei loro Chelati con il Rame (II)
Conformational studies on Cu(II) policomplexes of pyridoxal Schiff bases of polypeptides
Structures of Cu(II) complexes of pyridoxal Schiff bases with poly(l-lysine), poly(l-ornithine), and poly(l-α,γ-diaminobutyric acid) were investigated by absorption spectra, CD, and conformational analysis.
Although the polypeptides retain their typical right-handed α-helical conformation, opposite Cotton effects were found for the poly(l-lysine) and poly(l-ornithine) polycomplexes in the whole range of wavelengths from 600 to 250 nm. As in the analogous derivatives of salicyladehyde, this effect seems to be due to a stereospecific binding of the square planar Cu(II)-bis-pyridoxylideneimine group to the α-helical matrix. Circular dichroism spectrum of poly(l-α,γ-diaminobutyric acid) polycomplex is similar to that found for poly(l-lysine) derivative, but indicates large tetrahedral distortion of the square-planar coordination of copper ion