Liu Sizhi is quick-thinking and far-sighted in scientific research. He is one of the founders of immunochemistry. There is also research in the field of transsexuality in protein.
Biochemistry is a new subject in the 20th century. In 1960s, there were still different opinions about the mechanism of protein's degradation. China biochemist Hsien Wu studied protein degeneration in Peking Union Medical College on 1928- 1940, and Liu Sizhi was one of his assistants. 1929 In August, at the 13 International Physiology Conference held in Boston, USA, Hsien Wu read out "protein's theory of degeneration" summarized from a series of experiments, which was well received. The scientific experiments that laid the foundation for this theory of sex change were mainly completed by Liu Sizhi and other assistants. Experiments show that the denaturation of protein is that protein molecules change from folding to stretching. This theory has been confirmed in more experimental results in the future, and it is still recognized by the international biochemical community.
Immunochemistry research
As early as the 1930 s, the study of immune response was mainly a matter for microbiologists. At that time, the reaction between antigen and antibody was only qualitative with the naked eye, and little was known about the chemical nature of antibody. Under the leadership of Hsien Wu, Liu Sizhi creatively studied the antigen-antibody precipitation reaction by chemical quantitative method, analyzed the proportion of antigen-antibody in immune precipitate, and quantitatively recovered and purified the antibody. On this basis, Liu Sizhi studied the solubility and precipitation curve of immunoprecipitate and the reaction of antibody formation when two different antigens were injected at the same time, and became one of the founders of immunochemistry. Later, I continued my research in this field, such as studying the nature and metabolism of low-level antibodies, the influence of hormones on antibody metabolism, and the metabolic rate of different antigens in the body. Published more than 40 articles in domestic and foreign magazines.
Study on Protein Biosynthesis
As early as 1955, biosynthesis in protein was still a mysterious field. Liu Sizhi, in the Department of Biochemistry of Beijing Medical College, who he led, bravely drew up the strategic focus of scientific research "Biosynthesis in protein"; Therefore, advanced biochemical experimental techniques such as electrophoresis and chromatography were established earlier in the field of biochemistry in China, which made Fedoroff (иваивановичiд?), a Soviet expert, unfortunate in 1957. Another reason that affects the progress of his scientific research plan is to study the scientific research system of the Soviet Union, which is mainly composed of academy of sciences and research institutions. In the1960s, there was a major breakthrough in protein biosynthesis research in Europe and America, and Liu Sizhi's political situation improved slightly. He regrouped and drew up a scientific research plan with "antibody biosynthesis" as the breakthrough. He wrote his own scientific research ideas and viewpoints into the Nature and Production Mechanism of Antibodies, and published them in the Progress of Biological Science of 1963, in order to seek discussion from fellow researchers. At that time, the role of nucleic acid in genetic information transmission had just begun to take shape. He learned from the report of a French laboratory that introducing DNA extracted from Beijing duck into another strain of duck can lead to the transformation of some traits of the latter strain of duck into the characteristics of Beijing duck. He wants to extract DNA from lymphocytes of immunized animals and introduce it into another non-immunized homologous animal, hoping to obtain the transfer of antibody production performance, thus proving the way of DNA→mRNA→ antibody protein biosynthesis. It's a pity that this research work died shortly after it started because of the "Cultural Revolution". Liu Si regretted his unfulfilled ambition all his life.
Determine biochemical terms and write biochemical handouts
Before 1950, China not only didn't have a biochemistry textbook written in its own words, but even lacked a complete set of biochemistry terms in China. In view of this, after the victory of the Anti-Japanese War, Liu Sizhi organized some biochemists to discuss the Chinese manuscripts of biochemical terms, which was opposed by W. Adolph, then the head of the Department of Biochemistry of Peking Union Medical College and a former American professor in yenching university. Dou believes that this is out of the central task of Union Medical College. It was not until the beginning of 1950 that it was possible for Liu Sizhi to invite several peer experts to start writing biochemical terms. After distributing the draft terms to relevant experts all over the country for comments, they finally worked out a more systematic draft of biochemical terms. The draft was quickly adopted by the whole country, which unified the national biochemical terms and laid a good foundation for the compilation and publication of biochemical textbooks in the future. 1954 Edited by Biochemistry Outline, which is the first China biochemistry textbook compiled by China people. With 700,000 words, the book is rich in content, novel in materials, clear in organization and strong in logic. It is especially valuable to introduce the achievements in wine fermentation, nutrition and organ treatment in ancient China in the preface. He praised Hsien Wu's outstanding contributions in clinical chemistry, protein chemistry, especially protein's denaturation theory and immunochemistry. In the chapter of nutrition, combined with the specific situation of China, the requirements of adults in China for protein and other nutrients were revised; According to China's eating habits, this paper lists the physiological values of several kinds of mixed protein that China people eat every day, which makes the book change the past practice of copying foreign textbooks from science and technology textbooks. 1964, recommended by the Ministry of Health, the title was changed to Biochemistry, which was used as a trial textbook in medical colleges until 1978. 1950s, in order to popularize and train middle-level health cadres, Liu Sizhi also compiled a small biochemistry lecture for the amateur evening school of in-service cadres of the Ministry of Health of North China Military Region. The third edition of this lecture is published by Science Press 1965. The book is concise and easy to understand, and its writing is fluent, which is well received by the medical and health circles. 1? h？ Wu and s? c？ Liu, ultrasonic coagulation of ovalbumin, Chinese medical journal? Soc？ Exp？ Biol？ Medicine? , 193 1,28:782~784?
2? h？ Wu, s? c？ Liu and Qin Feng? y？ Study on coagulation denaturation of ovalbumin osmotic curve, China? j？ Physiologist? , 193 1,5:309~3 19.
3? s？ c？ Liu, h? Wu and b? f？ Separation of basic globulin components from normal and immunized horse serum. j？ Physiologist? , 1937, 1 1:2 1 1~222.
4? s？ c？ Liu and h? Wu, the best conditions for recovering antibodies from immunoprecipitation of pneumococcus type I, Chinese Journal of Medicine? Soc？ Exp？ Biol？ Medicine? , 1939,4 1: 144~ 148.
5? s？ c？ Liu and h? Wu, recovering antigen from immunoprecipitate of pneumococcus type I, Chinese Journal of Medicine? Soc？ Exp？ Biol？ Medicine? , 1940,43:747~749.
6? s？ c？ Liu and h? Wu, recovering antibodies from immunoprecipitation of B-bacilli, Chinese Journal of Medicine? Soc？ Exp？ Biol？ Medicine? , 1942,49:38 1~383.
7? Liu Sizhi, editor-in-chief, Outline of Biochemistry, People's Health Publishing House, 1954.
8? Liu Sizhi, Wang Shizhong, Immunological Characteristics of Lower Antibodies, Acta Biologica, 1958,1(2):141~149.
9? Liu Sizhi, Properties and Mechanism of Antibodies, Progress in Physiological Science,1963,5 (1):112.
10? Li Gang, Du Guoguang, Liu Sizhi, Comparison of metabolic rate and immune function of two different protein in rabbits, progress in biochemistry and biophysics, 1984, 1: 42 ~ 47. yellow