Biophysical studies on the interaction of the alkaloid chelerythrine with nucleic acids

DNA-deoxyribonucleic acid is the blueprint for life. It is present in organisms ranging from the smallest bacterium to the largest whale. DNA carries most of the genetic instructions used in the development, functioning and reproduction of well known living organisms. James Dewey Watson and Francis Harry Compton Crick had revolutionized the field of molecular biology and medicine by proposing the structure of deoxyribonucleic acid through model building studies in their celebrated paper published in the Nature magazine of April 23 (Watson and Crick, 1953). Although the Watson and Crick was known as father of DNA the preliminary research on DNA was started many decades ago on 1868 by Swiss chemist Friedrich Miescher. Miescher in 1868 detected a phosphorus-containing substance from the nuclei of pus cells obtained from discarded surgical bandages. He named it ‘nuclein’ consisting of an acidic portion which we know today as DNA. In 1878, Albrecht Kossel isolated the nonprotein component of “nuclein”, the nucleic acid, and later isolated its five primary nucleobases (Albrect, 1879). In 1919, Phoebus Levene identified the base, sugar and phosphate nucleotide unit (Levene, 1919). Levene suggested that DNA consisted of a string of nucleotide units linked together through the phosphate groups. Levene thought the chain was short and the bases repeated in a fixed order. In 1937, William Astbury produced the first X-ray diffraction pattern that showed that DNA had a regular structure (Astbury and Florence, 1938). In 1944 Oswald Avery and his coworkers discovered that DNA carries a cell’s genetic material and can be altered through transformatio