Effect of platinum(II) chemotherapeutic agents on properties of DNA liquid crystals

• Published in: Biophysical chemistry Vol. 35; no. 2; pp. 143 - 153
• Main Authors: Yevdokimov, Yu.M., Skuridin, S.G., Salyanov, V.I., Damaschun, G., Damaschun, H., Misselwitz, R., Kleinwächter, V.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.04.1990
• Subjects: Animals; Antineoplastic Agents - pharmacology; Circular Dichroism; Cisplatin - pharmacology; Crystallization; DNA - drug effects; DNA liquid crystal; Liquid-crystalline dispersion; Male; Molecular Weight; Optical texture; Organoplatinum Compounds - pharmacology; Platinum(II) coordination complex; Salmon - metabolism; Spermatozoa - metabolism; X-ray crystallography; X-Ray Diffraction; Platinum(II) coordination complex; X-ray crystallography; Liquid-crystalline dispersion; CD; Optical texture; DNA liquid crystal
• ISSN: 0301-4622; 1873-4200
• DOI: 10.1016/0301-4622(90)80004-Q

We have investigated the X-ray and optical properties (CD spectra and polarization microscopy) of liquid-crystalline phases and dispersions formed on pretreatrnent of low molecular weight DNA with the platinum(II) coordination complexes, cis-diammine-dichloroplatinum(II) (DDP), 2,2′ -bipyridinedichloroplatinum(II) ( 1) and 2,2′-bipyridineethylenediammineplatinum(II) ( 2). It is demonstrated that the platination of DNA leads to the ordering of neighbouring molecules of DNA in liquid-crystalline phases being diminished. The intense bands observed in the CD spectra of liquid-crystalline dispersions prepared from DNA pretreated with 1 or 2 can be used to determine the orientation of the latter compounds with respect to the helical axis of the DNA and to detect distortions in the secondary structure of DNA. The possible causes of the appearance of the intense bands in the CD spectra of liquid-crystalline phases and alterations in the manner of packing of the molecules of DNA within them are discussed.