ISSN:
0006-3525
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
The high-humidity X-ray pattern of oriented fibers prepared from salmon spermheads strongly resembles that of DNA in the B form. However, the nucleoprotamine pattern has a more intense first layer line and increased lateral unit-cell dimensions.Complexes of DNA with poly-L-lysine and poly-L-arginine were prepared and photographed at various relative humidities. The most crystalline patterns were obtained at 92% and also indicate DNA in the B form. However, whereas polylysine-DNA, like the spermheads, has a primitive hexagonal cell, polyarginine-DNA, like NaDNA, has three molecules in the unit cell. Polylysine-DNA, but not polyarginine-DNA, also resembles spermheads in having a strong first layer line.All three complexes show increasing intermolecular distance with increasing humidity, but with sharp maxima when photographed in water, which indicates cross-linking between the molecules. Lowering the humidity causes the polylysine-DNA, but not polyarginine-DNA, to change conformation from the B to the C form.The structural implications of these results are discussed in the light of model-building studies and a comparison of calculated and observed X-ray intensities.
Additional Material:
5 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bip.1972.360111103
