L-lactate dehydrogenase activity

Definition

Target type: molecularfunction

Catalysis of the reaction: (S)-lactate + NAD+ = pyruvate + NADH + H+. [EC:1.1.1.27, RHEA:23444]

L-lactate dehydrogenase (LDH) catalyzes the interconversion of pyruvate and L-lactate, an essential reaction in cellular metabolism. This reversible reaction plays a crucial role in the following:

1. **Glycolysis:** During glycolysis, pyruvate is produced from glucose. When oxygen is limited, LDH reduces pyruvate to lactate, regenerating NAD+ which is required for further glycolysis. This allows for ATP production even in the absence of oxygen, crucial for anaerobic metabolism.

2. **Gluconeogenesis:** In the liver, LDH can convert lactate back to pyruvate, which can then be used for gluconeogenesis to generate glucose. This is important for maintaining blood glucose levels, especially during prolonged fasting or exercise.

3. **Lactate shuttle:** LDH facilitates the transfer of lactate from tissues with high glycolytic activity (e.g., muscle) to tissues with high oxidative capacity (e.g., liver). This process is known as the lactate shuttle, and it allows for the efficient use of lactate as a fuel source.

4. **Regulation of redox balance:** LDH contributes to the regulation of cellular redox state by interconverting pyruvate and lactate, which are both involved in the transfer of electrons and the production of NADH/NAD+ and FADH2/FAD.

5. **Other physiological functions:** LDH has been implicated in various other biological processes, including immune responses, cell signaling, and tumor growth. The specific role of LDH in these processes is still being investigated.

The activity of LDH is influenced by several factors, including the availability of substrates (pyruvate and lactate), the cellular energy state, and the presence of specific inhibitors or activators.'
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Proteins (3)

Compounds (18)