Creatinase

Creatinase

Structure of creatinase enzyme

Creatinase is an enzyme that catalyzes the hydrolysis of creatine to sarcosine and urea. It plays a crucial role in the metabolism of creatine, a compound that is important for energy storage in muscle and brain tissue.

Structure

Creatinase is a homodimeric enzyme, meaning it consists of two identical subunits. Each subunit contains an active site where the substrate, creatine, binds and undergoes catalysis. The enzyme's structure has been elucidated using X-ray crystallography, revealing important details about its active site and mechanism of action.

Function

The primary function of creatinase is to break down creatine into sarcosine and urea. This reaction is part of the creatine degradation pathway, which is essential for maintaining the balance of creatine in the body. The enzyme is found in various organisms, including bacteria, where it is involved in the utilization of creatine as a nitrogen source.

Mechanism

Creatinase catalyzes the hydrolysis of creatine by facilitating the nucleophilic attack of a water molecule on the guanidino group of creatine. This reaction results in the cleavage of the carbon-nitrogen bond, producing sarcosine and urea. The enzyme's active site contains key amino acid residues that stabilize the transition state and facilitate the reaction.

Clinical Significance

Creatinase is used in clinical laboratories as part of assays to measure creatine and creatinine levels in biological samples. These measurements are important for diagnosing and monitoring conditions such as kidney disease and muscle disorders.

Industrial Applications

In addition to its clinical applications, creatinase is used in the food industry for the production of flavor enhancers and in the synthesis of biodegradable polymers. Its ability to specifically hydrolyze creatine makes it a valuable tool in various biotechnological processes.

Related pages

• Creatine
• Sarcosine
• Urea
• Enzyme
• Metabolism