Acetoacetate decarboxylase

Acetoacetate decarboxylase

Structure of acetoacetate decarboxylase biounit 3BH3

Acetoacetate decarboxylase is an enzyme that catalyzes the decarboxylation of acetoacetate to produce acetone and carbon dioxide. This enzyme plays a crucial role in the ketone body metabolism pathway, particularly in organisms that utilize ketone bodies as an energy source.

Structure

Acetoacetate decarboxylase is a homotetrameric enzyme, meaning it consists of four identical subunits. Each subunit contains an active site where the decarboxylation reaction occurs. The enzyme's structure is stabilized by interactions between the subunits, which are essential for its catalytic activity.

Active site of acetoacetate decarboxylase

Mechanism

The catalytic mechanism of acetoacetate decarboxylase involves the formation of a Schiff base intermediate between the substrate, acetoacetate, and a lysine residue in the active site. This intermediate facilitates the release of carbon dioxide, resulting in the formation of acetone.

Mechanism of acetoacetate decarboxylase

Active Site

The active site of acetoacetate decarboxylase contains several key residues, including lysines, that are critical for its function. These residues participate in substrate binding and catalysis.

Lysines in the active site of acetoacetate decarboxylase

Function

Acetoacetate decarboxylase is involved in the ketogenesis pathway, where it converts acetoacetate, a ketone body, into acetone. This reaction is important in organisms that rely on ketone bodies as an alternative energy source, such as during prolonged fasting or in diabetic conditions.

Applications

Understanding the function and mechanism of acetoacetate decarboxylase can have applications in biotechnology and medicine. For example, manipulating this enzyme's activity could potentially influence ketone body levels in metabolic disorders.

Related pages

• Ketone bodies
• Ketogenesis
• Acetone
• Enzyme

Gallery

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  Reporter molecule scheme related to acetoacetate decarboxylase

Acetoacetate_decarboxylase

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  Acetoacetate decarboxylase biounit structure with inset

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  Active site of acetoacetate decarboxylase

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  Final mechanism of acetoacetate decarboxylase

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  Reporter molecule scheme by Westheimer

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  Lysines in the active site of acetoacetate decarboxylase