RESUMO
Both cis- and trans-platins are known to form intra- and interstrand cross-linking with DNA. Since the nature and strength of binding is different, it makes their efficacy as anti-tumour drug different. In the present communication, we report theoretical analysis by using an amended Zimm and Bragg theory, to explain the melting behaviour and heat capacity of DNA with and without platin binding. The sharpness of transition has been examined in terms of half width and sensitivity parameter (deltaH/sigma). The experimental measurements of Pilch et al (J Mol Biol 2000, 296, 803) and Ctirad and Brabec (J Biol Chem 2001, 276, 9655) have been used.
Assuntos
Antineoplásicos/química , Cisplatino/química , DNA/efeitos dos fármacos , Algoritmos , Antineoplásicos/farmacologia , Sequência de Bases , Reagentes de Ligações Cruzadas/química , DNA/química , Temperatura Alta , Humanos , Modelos Químicos , Modelos Teóricos , Dados de Sequência Molecular , Conformação de Ácido Nucleico , Ligação Proteica , Estrutura Terciária de Proteína , TemperaturaRESUMO
A study of the normal modes of vibration and their dispersion in polyinosinic acid [poly (I)] along the helix axis based on Urey-Bradley force field is reported. It leads to a better interpretation of Raman and FTIR spectra. A comparison of dispersion curves of poly (I) with poly (G) has been made. Characteristic features of dispersion curves, such as regions of high density-of-states, repulsion and character mixing are discussed. Predictive value of heat capacity as a function of temperature is reported.
Assuntos
Poli I/química , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Análise de Fourier , Temperatura Alta , Cinética , Modelos Químicos , Modelos Teóricos , Fônons , Reprodutibilidade dos Testes , Análise Espectral Raman/métodos , Temperatura , VibraçãoRESUMO
The collective normal modes of the hexapeptide -Ser-Cys-Lys-Leu-Asp-Phe-, a fragment of apolipoprotein B (apo B), have been obtained. They reflect the dynamic nature and are atleast partly responsible for energy input in autolytic activity. Further, on energetic considerations based on the measurements reported by Sim & Sim, it has been shown that of the two such fragments only one induces autolysis, while the other remains anchored to the coated pit.