[3] Their broad substrate specificity, their ability to strongly bind to their targets, allows them to remove beginning N-terminal amino acids from almost all unsubstituted oligopeptides.

[4] For instance, Aminopeptidase N (AP-N) is particularly abundant in the brush border membranes of the kidney, the small intestine, and the placenta, and is also found in the liver.

[4] AP-N is involved in the final digestion of peptides generated from the hydrolysis (cleaving) of proteins by gastric and pancreatic proteases.

The term "aminopeptidase" was first introduced in 1929 by Linderstrøm-Lang and Sato in order to describe enzymes that cleave amino acids from the N-terminus of peptides.

[7] Aminopeptidase N, also known as AP-N or CD13, was extensively characterized for its broad substrate specificity (ability to bind to its targets) and its presence in various tissues such as the brush border membranes of the kidney, small intestine, and placenta.

[4] The enzyme's role in brain function and its identification as the human cluster differentiation antigen CD13 on the surface of myeloid cells further highlighted its biological significance.

[citation needed] Aminopeptidases are a diverse group of enzymes that play crucial roles in various biological processes, including protein digestion, cell growth, and immune response.

They are classified based on their substrate specificity (strength of binding) and catalytic mechanism (means of catalyzing their reaction) into two main categories: metalloaminopeptidases and cysteine aminopeptidases.

[13] They and can be found in many different cellular locations, for example in the cytoplasm, in membranes, associated with the cell envelope,[clarification needed] or secreted into the extracellular medium.

For example, leucine aminopeptidase (LAP) from Aspergillus species has been found to be thermostable and could theoretically be used to control the degree of hydrolysis and flavor development in a wide range of substances.

[4] It has a broad substrate specificity (ability to bind to its targets) and is involved in the final stages of the digestion of peptides generated from breaking-up and hydrolysis of proteins by gastric and pancreatic proteases.

Inhibitors of APN have demonstrated anti-inflammatory effects in animal models, positioning them as potential therapeutic agents for these conditions.

This enzymatic action contributes significantly to the development of the cheese's flavor and texture, making aminopeptidases essential in the cheese-making process.

[16] It is important to handle these enzymes under conditions that prevent contamination and degradation, which could affect both the safety and quality of the food products.

[17] These examples indicate that aminopeptidases generally require neutral pH conditions and can be stored at low temperatures, such as -20°C or -80°C, for extended periods to preserve their activity.