Official Full Name
3-HBDH
Background
In enzymology, 3-hydroxybutyrate dehydrogenase (EC 1.1.1.30) is an enzyme that catalyzes the chemical reaction:
(R)-3-hydroxybutanoate + NAD+ ⇋ acetoacetate + NADH + H+
Thus, the two substrates of this enzyme are (R)-3-hydroxybutanoate and NAD+, whereas its three products are acetoacetate, NADH, and H+. This enzyme belongs to the family of oxidoreductases, to be specific, those acting on the CH-OH group of donor with NAD+ or NADP+ as acceptor.
This enzyme participates in the synthesis and degradation of ketone bodies and the metabolism of butyric acid.
Synonyms
3-hydroxybutyrate dehydrogenase; 3-HBDH; NAD-β-hydroxybutyRate dehydrogenase; hydroxybutyRate oxidoreductase; β-hydroxybutyRate dehydrogenase; D-β-hydroxybutyRate dehydrogenase; D-3-hydroxybutyRate dehydrogenase; D-(–)-3-hydroxybutyRate dehydrogenase; β-hydroxybutyric acid dehydrogenase; 3-D-hydroxybutyRate dehydrogenase; β-hydroxybutyric dehydrogenase; EC 1.1.1.30; 9028-38-0
The 3-Hydroxybutyrate Dehydrogenase (3-HBDH) enzyme is a crucial protein found in the human body. It plays a vital role in energy metabolism and serves as a valuable biomarker in clinical diagnosis. This review aims to explore the various aspects of 3-HBDH, including its structure, function, clinical significance, applications, and conclusions. The 3-Hydroxybutyrate Dehydrogenase (3-HBDH) enzyme is a crucial protein found in the human body. It plays a vital role in energy metabolism and serves as a valuable biomarker in clinical diagnosis. This review aims to explore the various aspects of 3-HBDH, including its structure, function, clinical significance, applications, and conclusions.
Structure
The main function of 3-HBDH is to catalyze the reversible conversion of 3-hydroxybutyrate to acetoacetate, an essential step in ketone body metabolism. It performs this reaction by utilizing a nicotinamide adenine dinucleotide (NAD+) cofactor. The enzyme's activity is regulated by various factors, including pH, temperature, and substrate concentration. The proper functioning of 3-HBDH is crucial for maintaining metabolic homeostasis.
Active Sites
The catalytic activity of 3-HBDH is facilitated through specific active sites present in each subunit. The enzyme contains both a coenzyme binding site and a substrate binding site.
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Coenzyme Binding Site: The coenzyme binding site of 3-HBDH accommodates the nicotinamide adenine dinucleotide (NAD+ or NADH) coenzyme, which plays a crucial role in the enzymatic reaction. NAD+ acts as an electron acceptor during the oxidation of 3-hydroxybutyrate to acetoacetate, while NADH functions as an electron donor during the reverse reaction.
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Substrate Binding Site: The substrate binding site of 3-HBDH accommodates 3-hydroxybutyrate, the primary substrate of the enzyme. This site facilitates the selective binding of the substrate, allowing for the enzymatic conversion of 3-hydroxybutyrate to acetoacetate, or vice versa.
Functions
In the dogfish shark, the main function of 3-HBDH is to help with the breakdown of ketone bodies in the cells. This function is supported by experimental evidence of starved dogfish sharks after they are fed. When starved, the ketone levels in the shark bodies increase, especially after long-term starvation. Once they are fed, the presence of ketone bodies in the body declines rapidly. The rapid decline is correlated with significant elevations of BHBDH activity, which points towards this enzyme being very important to process ketone bodies
Clinical Significance
The 3-HBDH enzyme has also shown prognostic significance in certain pathological conditions, such as acute pancreatitis and cerebral infarction. Studies have demonstrated that measuring the enzyme activity can help predict the severity and outcome of these diseases, aiding in appropriate clinical management decisions.
The measurement of 3-HBDH activity has gained significant clinical importance as a diagnostic marker for several pathological conditions. Elevated levels of 3-HBDH have been observed in various liver, heart, and muscle disorders, such as hepatitis, myocardial infarction, and myopathy. Monitoring the enzyme activity can aid in early diagnosis, prognosis, and treatment monitoring for these diseases.
Conclusion
3-HBDH enzyme has become an important participant in energy metabolism and an important biomarker for clinical diagnosis. Its structure, function, clinical significance, and application have been intensively studied, revealing its important role in maintaining metabolic homeostasis. Further studies are necessary to explore its potential therapeutic applications and to facilitate the development of interventions for related diseases. In conclusion, the 3-HBDH enzyme holds great promise in both research and clinical settings. Its multifaceted role, diagnostic significance, and potential therapeutic applications make it an area of great interest.
