Open AccessOptical Rotatory Dispersion and Nuclear Magnetic Resonance
Author(s) -
Boublík M.,
Bradbury E. M.,
CraneRobinson C.,
Rattle H. W. E.
Publication year - 1970
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1970.tb00845.x
Subject(s) - optical rotatory dispersion , lysine , arginine , helix (gastropod) , aqueous solution , ionic strength , polymer , chemistry , histone , crystallography , polyelectrolyte , circular dichroism , nuclear magnetic resonance , polymer chemistry , amino acid , organic chemistry , biochemistry , dna , physics , biology , ecology , snail
The helix→coil transitions of poly‐ l ‐arginine and poly‐ l ‐lysine are compared with that of calf thymus histone, using spectroscopic methods. Although poly‐ l ‐lysine can be obtained in helical form in water by raising pH or ionic strength, this is not found to be possible with poly‐ l ‐arginine. Optical rotatory dispersion data for the synthetic polypeptides indicate sharp transitions when certain organic solvents are added to aqueous solutions. Calf thymus histone by contrast shows a gradual change in helicity as organic solvents are added. The high resolution nuclear magnetic resonance spectra of poly‐ l ‐lysine and poly‐ l ‐arginine in aqueous methanol mixtures have been obtained. The αCH peak position is found to depend on the polymer conformation and for fully helical poly‐ l ‐arginine lies at approx. 6.0.