大学化学 >> 2019, Vol. 34 >> Issue (4): 77-83.doi: 10.3866/PKU.DXHX201806016

师生笔谈 上一篇    下一篇

生物化学中酶促“不可逆”反应及其相关问题辨析

马新雨1,王志鹏1,4,*(),田杰3,蒋振雄3,姜汉杰4,孙鹤5,周青璇6,王鑫2,*()   

  1. 1 Department of Chemistry, Texas A & M University, College Station, TX 77840, USA
    2 Department of Microbiology, Miami University, Oxford, OH 45056, USA
    3 Department of Biology, Texas A & M University, College Station, TX 77840, USA
    4 Division of Genetics, Department of Medicine, Brigham and Women's Hospital; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
    5 南方科技大学化学系, 广东 深圳 518055
    6 Broad Institute of MIT and Harvard, Cambridge; Department of Medicine, Harvard Medical School; Renal Division, Brigham and Women's Hospital, Boston, MA 02142, USA
  • 收稿日期:2018-06-15 录用日期:2018-07-17 发布日期:2019-04-28
  • 通讯作者: 王志鹏,王鑫 E-mail:wzpchem1991@gmail.com;xwang@tamu.edu

Discussion on the Definition of "Irreversible" Reactions and Its Related Concepts in Biochemistry

Xinyu MA1,Zhipeng A. WANG1,4,*(),Jie TIAN3,Zhenxiong JIANG3,Hanjie JIANG4,He SUN5,Qingxuan ZHOU6,Xin WANG2,*()   

  1. 1 Department of Chemistry, Texas A & M University, College Station, TX 77840, USA
    2 Department of Microbiology, Miami University, Oxford, OH 45056, USA
    3 Department of Biology, Texas A & M University, College Station, TX 77840, USA
    4 Division of Genetics, Department of Medicine, Brigham and Women's Hospital; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
    5 Department of Chemistry, Southern University of Science and Technology, Shenzhen 518055, Guangdong Province, P. R. China
    6 Broad Institute of MIT and Harvard, Cambridge; Department of Medicine, Harvard Medical School; Renal Division, Brigham and Women's Hospital, Boston, MA 02142, USA
  • Received:2018-06-15 Accepted:2018-07-17 Published:2019-04-28
  • Contact: Zhipeng A. WANG,Xin WANG E-mail:wzpchem1991@gmail.com;xwang@tamu.edu

摘要:

在生物化学教学和研究中,一些酶促反应被归类为不可逆反应。然而,此处的"不可逆"与物理化学中的"不可逆"有所不同,这一表述本身常导致学生的困惑。不仅如此,"不可逆"的实际含义及其衍生的观念可能进一步使学生产生很多对基本生化反应过程的严重误解。本文以物理化学所定义的"不可逆"为准,重新讨论生物化学中所指"不可逆"的准确含义,并举例讨论了包括"速控步""限速酶""高能磷酸键"在内的若干因生物化学中"不可逆"的不准确定义造成的认知误区。

关键词: 酶促反应, 可逆反应, 化学平衡

Abstract:

Some of the enzyme catalysis reactions were classified as irreversible in the biochemistry education and research. However, it is worth noting that the "irreversibility" defined in biochemistry is different from what is referred in physical chemistry, which often confuses students. Consequently, the essence of irreversibility and its derivative may mislead students to a fallacious understanding towards the reaction process of biochemical reactions. This manuscript anew discusses the precise definition of "irreversible" reactions in biochemistry based on the standard definition of "irreversibility" given in physical chemistry, and we further use several terms and examples including rate limiting step, rate limiting enzyme, and high-energy phosphate bond to identify and correct misunderstandings caused by inaccurate definition of irreversibility.

Key words: Enzyme catalysis, Reversible reaction, Chemical equilibrium

MSC2000: 

  • G64