allosteric enzyme

简明释义

变构酶

英英释义

例句

1.The feedback inhibition mechanism is a classic example of how allosteric enzymes work in metabolic control.

反馈抑制机制是变构酶在代谢控制中如何工作的经典例子。

2.Inhibitors can bind to an allosteric enzyme, altering its conformation and reducing its activity.

抑制剂可以与变构酶结合，改变其构象并降低其活性。

3.Research has shown that certain drugs act on allosteric enzymes to enhance their function.

研究表明某些药物通过作用于变构酶来增强其功能。

4.The regulation of metabolic pathways often involves an allosteric enzyme, which can change its activity in response to different molecules.

代谢途径的调节通常涉及一个变构酶，它可以根据不同分子的反应来改变其活性。

5.An allosteric enzyme can have multiple binding sites, allowing for complex regulatory mechanisms.

变构酶可以有多个结合位点，从而允许复杂的调节机制。

作文

Allosteric enzymes play a crucial role in the regulation of metabolic pathways within living organisms. These enzymes are unique because they do not follow the classic Michaelis-Menten kinetics that most enzymes do. Instead, they exhibit a phenomenon known as allosteric regulation, which is essential for maintaining homeostasis in biological systems. The term allosteric enzyme refers to an enzyme whose activity is modulated by the binding of an effector molecule at a site other than the active site. This binding can lead to conformational changes in the enzyme, thereby enhancing or inhibiting its activity.The importance of allosteric enzymes can be seen in various metabolic processes. For instance, in the glycolytic pathway, phosphofructokinase is a well-known allosteric enzyme that regulates the conversion of fructose-6-phosphate to fructose-1,6-bisphosphate. This step is critical because it serves as a major control point in glycolysis. When energy levels are high, ATP acts as an inhibitor of phosphofructokinase, decreasing the enzyme's activity and thus slowing down glycolysis. Conversely, when energy levels are low, ADP and AMP serve as activators, increasing the enzyme's activity and promoting glycolysis to produce more ATP.The mechanism of allosteric enzymes involves the binding of molecules to sites distinct from the active site, known as allosteric sites. This interaction induces a change in the enzyme's structure, which can either enhance or decrease its catalytic efficiency. This property allows cells to respond swiftly to changes in their environment or internal conditions. For example, during times of stress or increased energy demand, allosteric enzymes can quickly adjust their activity to meet the cell’s needs without the need for new enzyme synthesis.Moreover, the concept of cooperativity is often associated with allosteric enzymes. Many of these enzymes are composed of multiple subunits, and the binding of a substrate to one subunit can influence the activity of others. This cooperative behavior results in a sigmoidal curve when plotting reaction velocity against substrate concentration, contrasting with the hyperbolic curve seen in non-allosteric enzymes. This characteristic allows for more precise control over metabolic flux, enabling cells to finely tune their biochemical pathways.In summary, allosteric enzymes are fundamental components of biological regulation. Their ability to undergo conformational changes in response to effector molecules ensures that metabolic pathways can be adjusted according to the physiological needs of the organism. Understanding allosteric enzymes is essential for biochemists and molecular biologists, as it provides insights into the intricate networks of life at the molecular level. Research into these enzymes has implications for drug development and therapeutic interventions, particularly in diseases where metabolic regulation goes awry, such as diabetes and cancer. Therefore, further studies on allosteric enzymes will continue to be an important area of focus in the field of biochemistry and medicine.

变构酶在生物体内的代谢途径调节中发挥着至关重要的作用。这些酶是独特的，因为它们不遵循大多数酶的经典米氏动力学。相反，它们表现出一种称为变构调节的现象，这对于维持生物系统的稳态至关重要。术语变构酶指的是一种其活性通过效应分子在活性位点以外的位点结合而调节的酶。这种结合可以导致酶的构象变化，从而增强或抑制其活性。变构酶的重要性可以在各种代谢过程中看到。例如，在糖酵解途径中，磷酸果糖激酶是一种著名的变构酶，它调节果糖-6-磷酸转化为果糖-1,6-二磷酸的过程。这一步是关键的，因为它作为糖酵解中的主要控制点。当能量水平高时，ATP作为磷酸果糖激酶的抑制剂，降低酶的活性，从而减缓糖酵解过程。相反，当能量水平低时，ADP和AMP作为激活剂，增加酶的活性，促进糖酵解以产生更多的ATP。变构酶的机制涉及分子在不同于活性位点的位点结合，称为变构位点。这种相互作用会引发酶结构的变化，可能增强或降低其催化效率。这一特性使细胞能够迅速响应环境或内部条件的变化。例如，在压力或能量需求增加时，变构酶可以迅速调整其活性，以满足细胞的需求，而不需要新的酶合成。此外，合作效应的概念通常与变构酶相关联。许多这些酶由多个亚基组成，底物与一个亚基的结合可以影响其他亚基的活性。这种协同行为导致当绘制反应速度与底物浓度的关系时呈现S型曲线，这与非变构酶的双曲线形成对比。这一特性使得代谢通量能够更精确地控制，使细胞能够微调其生化途径。总之，变构酶是生物调节的基本组成部分。它们在响应效应分子时发生构象变化的能力确保了代谢途径可以根据生物体的生理需求进行调整。理解变构酶对于生物化学家和分子生物学家至关重要，因为它提供了关于生命在分子层面上复杂网络的见解。对这些酶的研究对药物开发和治疗干预有重要意义，尤其是在代谢调节失常的疾病中，如糖尿病和癌症。因此，进一步研究变构酶将继续成为生物化学和医学领域的重要研究方向。