Thermolysin

Structure of thermolysin

Thermolysin is a metalloprotease enzyme that is produced by the bacterium Bacillus thermoproteolyticus. It is a member of the peptidase family M4 and is known for its ability to cleave peptide bonds in proteins. Thermolysin is widely used in biotechnology and biochemistry due to its stability at high temperatures and its specificity for certain peptide bonds.

Structure

Thermolysin is a single polypeptide chain composed of approximately 316 amino acids. It has a molecular weight of about 34,600 daltons. The enzyme's active site contains a zinc ion, which is essential for its catalytic activity. The structure of thermolysin has been extensively studied using X-ray crystallography, revealing a compact, globular shape with a deep active site cleft.

Function

Thermolysin functions by cleaving peptide bonds in proteins, preferentially at the N-terminal side of hydrophobic amino acids such as leucine, isoleucine, and phenylalanine. This specificity makes it useful for various applications, including the production of aspartame, a low-calorie sweetener, and the synthesis of peptides.

Applications

Thermolysin is used in the food industry for the production of flavor enhancers and in the pharmaceutical industry for the synthesis of peptide drugs. Its ability to function at high temperatures makes it ideal for industrial processes that require elevated temperatures.

Stability

One of the key features of thermolysin is its thermal stability. It remains active at temperatures up to 80°C, which is higher than most other proteases. This stability is attributed to its compact structure and the presence of calcium ions that stabilize the enzyme.

Related pages

• Protease
• Metalloprotease
• Enzyme
• Bacillus thermoproteolyticus