Changes in the c.d. spectra of calf thymus DNA induced by sequential polypeptides in aqueous solutions. Part I.
Interactions of calf thymus DNA with sequential polypeptides were studied using c.d. spectroscopy in aqueous solutions. It was found that DNA structural alterations induced by sequential polypeptides (L-Arg-X-Gly)n (where X = L-Val, Leu, Ile, Nva, Nle) are modulated by the nature of the X residue. Thus, the polypeptide (L-Arg-L-Nva-Gly)n induced the 10.2B-DNA form, whereas the polypeptides (L-Arg-L-Ile-Gly)n having one methyl group less on the X residue side chain, did not provide any significant modification to the structure of DNA. The effect of ionic strength from 0.14 M NaCl (physiological value) to zero was also analysed on the basis of the observed c.d. changes and the degree of complexation in the DNA-polypeptides was estimated.
Tsikaris
V
V
Department of Chemistry, University of Ioannina, Greece.
Panou-Pomonis
E
E
Sakarellos
C
C
Sakarellos-Daitsiotis
M
M
Marraud
M
M
D000595:Amino Acid Sequence; D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D004247:DNA / Q000737:chemistry*; D004563:Electrochemistry; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry*; D012996:Solutions; D013950:Thymus Gland / Q000378:metabolism
D010455:Peptides; D012996:Solutions; D004247:DNA