Biomaterial Database

Preferential interstrand cross-linking of DNA rich in guanine and cytosine by cis-dichlorodiammineplatinum(II). 1979

P K Ganguli, and T Theophanides

Two native DNAs differing in G + C content were bound equally with the antitumour drug cis-Pt(NH3)2Cl2 at increasing Pt/P ratios. Resulting changes in their ultraviolet absorption spectra show equal fractional decreases in the initially different values of A250/A270 for the two DNAs, and less prominent bathochromic and hyperchromic shifts for DNA richer in G + C. Changes in the absorbance (A260) observed before and after subjecting the DNA samples to the conditions of denaturation (with alkali) and renaturation, indicate the following effects of the platinum binding. Maximum renaturation occurs at 50% lower Pt/P ratio of 0.03 for Micrococcus lysodeikticus DNA (72% G + C) than 0.06 for salmon sperm DNA (41% G + C) and is maintained at higher Pt/P ratios. Interstrand cross-links that facilitate renaturation, cause an incomplete melting of DNA so that the platinum-DNA complex at pH 12.5 has a reduced absorbance. This effect is more evident for the platinum complex with DNA richer in G + C due to more interstrand cross-links. Platinum-induced destabilisation of DNA, shown by its hyperchromicity at the pre-melting state (pH 6--7, 25 degrees C) and also by a lowering of the pH corresponding to the mid-point of its melting, is less evident for DNA richer in G + C.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008297	Male		Males
D008837	Micrococcus	A genus of gram-positive, spherical bacteria found in soils and fresh water, and frequently on the skin of man and other animals.
D002621	Chemistry	A basic science concerned with the composition, structure, and properties of matter; and the reactions that occur between substances and the associated energy exchange.
D002945	Cisplatin	An inorganic and water-soluble platinum complex. After undergoing hydrolysis, it reacts with DNA to produce both intra and interstrand crosslinks. These crosslinks appear to impair replication and transcription of DNA. The cytotoxicity of cisplatin correlates with cellular arrest in the G2 phase of the cell cycle.	Platinum Diamminodichloride,cis-Diamminedichloroplatinum(II),cis-Dichlorodiammineplatinum(II),Biocisplatinum,Dichlorodiammineplatinum,NSC-119875,Platidiam,Platino,Platinol,cis-Diamminedichloroplatinum,cis-Platinum,Diamminodichloride, Platinum,cis Diamminedichloroplatinum,cis Platinum
D003432	Cross-Linking Reagents	Reagents with two reactive groups, usually at opposite ends of the molecule, that are capable of reacting with and thereby forming bridges between side chains of amino acids in proteins; the locations of naturally reactive areas within proteins can thereby be identified; may also be used for other macromolecules, like glycoproteins, nucleic acids, or other.	Bifunctional Reagent,Bifunctional Reagents,Cross Linking Reagent,Crosslinking Reagent,Cross Linking Reagents,Crosslinking Reagents,Linking Reagent, Cross,Linking Reagents, Cross,Reagent, Bifunctional,Reagent, Cross Linking,Reagent, Crosslinking,Reagents, Bifunctional,Reagents, Cross Linking,Reagents, Cross-Linking,Reagents, Crosslinking
D003596	Cytosine	A pyrimidine base that is a fundamental unit of nucleic acids.
D004247	DNA	A deoxyribonucleotide polymer that is the primary genetic material of all cells. Eukaryotic and prokaryotic organisms normally contain DNA in a double-stranded state, yet several important biological processes transiently involve single-stranded regions. DNA, which consists of a polysugar-phosphate backbone possessing projections of purines (adenine and guanine) and pyrimidines (thymine and cytosine), forms a double helix that is held together by hydrogen bonds between these purines and pyrimidines (adenine to thymine and guanine to cytosine).	DNA, Double-Stranded,Deoxyribonucleic Acid,ds-DNA,DNA, Double Stranded,Double-Stranded DNA,ds DNA
D004269	DNA, Bacterial	Deoxyribonucleic acid that makes up the genetic material of bacteria.	Bacterial DNA
D006147	Guanine