生物化学II（苏维恒）核酸的结构与性质.pptVIP

极端酶与肿瘤纳米医学课题组 课程内容——核酸部分 静态生物化学 核酸的研究历史 核酸的结构 核酸的性质 动态生物化学 核酸的降解与核苷酸代谢 Nucleic acid History of nucleic acid Nucleotides are the building blocks of nucleic acids DNA and RNA structure Nucleic acid properties History of Nucleic Acids (before 1953) History of DNA 1869 – DNA was first identified by Friedrich Miescher, a Swiss biologist. He called the substance nuclein, noted the presence of phosphorous, and separated the substance into an acidic part (which we now know is DNA) and a basic part (a class of basic proteins that bind to acidic DNA). 1889 – The term “nucleic acid” was first used by Richard Altmann, a German pathologist and histologist. Friedrich Miescher Friedrich Miescher (Swiss, 1844-1895) Intelligent from early age but very shy Studied at the University of Tübingen (图宾根大学 )under Hoppe-Seyler, considered the father of biochemistry Friedrich Miescher’s discovery He examined used bandages obtained from a hospital caring for the wounded of the Crimean War in hope of finding something interesting He discovered a substance containing both phosphorus and nitrogen, made up of molecules that were apparently very large, in the nuclei of white blood cells found in pus Named the substance nuclein because it seemed to come from cell nuclei. In 1874 when Miescher separated it into a protein and an acid molecule. It is now known as deoxyribonucleic acid (DNA) Hoppe-Seyler This substance was so unusual that Hoppe-Seyler repeated the work himself before allowing Miescher to publish the paper on the discovery He found an excellent (and more pleasant) source of nuclear material in the sperm of the salmon The nuclei are large in any sperm cells, remarkably so in the salmon’s From these he first extracted a pure DNA Tetranucleotide Hypothesis Phoebus Levene (Russian-American, 1869-1940) (sugar in DNA and chemical bond) He worked with Albrecht Kossel (base, Nobel Prize) and Emil Fischer, the nucleic acid and protein experts at the t