Proteases are critical in maintaining cellular homeostasis by degrading damaged, misfolded, or unwanted proteins, allowing protein turnover and recycling of amino acids. However, proteases also play essential roles in various biological processes. For example, proteases are responsible in providing cellular nutrients by breaking down dietary proteins into smaller peptides and amino acids during the process of digestion. In humans, they are produced in the stomach (e.g., pepsin) or small intestine (e.g., trypsin, chymotrypsin, and carboxypeptidases) and facilitate the breakdown of proteins into absorbable nutrients. Some proteases participate in intracellular signalling pathways by cleaving and activating (or inactivating) specific proteins. For example, caspases play a crucial role in initiating and executing apoptosis by proteolysis, whilst ADAM (A Disintegrin And Metalloproteinase) are involved in the proteolytic shedding of cell surface proteins, including growth factors, cytokines, receptors, and adhesion molecules. ADAM proteases cleave these proteins near the cell membrane, leading to their inactivation and release of soluble forms. Certain proteases, such as thrombin and plasmin, are involved in the important repair processes of the blood clotting cascade and fibrinolysis, respectively. By regulating the formation and dissolution of blood clots they promote wound healing and prevent excessive bleeding. Proteases are also involved in various aspects of the immune response. Firstly, they can process antigenic proteins into smaller fragments for presentation by major histocompatibility complex (MHC) molecules, facilitating immune recognition. Proteasomes generate peptides that are later utilized in antigen presentation, whilst aminopeptidases trim the N-terminal ends of peptides generated by proteasomes. Aminopeptidases, such as ERAP1 (Endoplasmic Reticulum Aminopeptidase 1) and ERAP2, are involved in shaping the peptide repertoire for major histocompatibility complex class I (MHC-I) presentation, whilst lysosomal proteases such as cathepsins S, -L, and -D, contribute to the generation of peptides for MHC-II presentation. An additional protease, dipeptidyl peptidase 4 (DPP4) also known as CD26, is involved in the final trimming of MHC-II-associated peptides before their presentation. It removes dipeptides from the N-terminus of antigenic peptides, influencing their stability and affinity for MHC-II molecules. Some proteases, particularly matrix metalloproteinases (MMPs), are also important for the breakdown and remodelling of the extracellular matrix (ECM) during embryonic development, wound healing, and tissue repair, whilst others are responsible for the cleavage and activation of inactive peptide hormones or prohormones into their active forms. For example, the enzyme proprotein convertase is involved in the maturation of various peptide hormones. Major classes of proteases include: 1) serine proteases, a large and diverse group of enzymes that contain a serine residue in their active sites. Examples include trypsin, chymotrypsin, and elastase. Serine proteases are involved in various physiological processes, such as digestion, blood clotting, and immune response; 2) cysteine proteases, which use a cysteine residue in their active sites to catalyse proteolysis. Papain and caspases are examples of such cysteine proteases; 3) aspartic proteases, which have two aspartic acid residues in their active sites involved in the hydrolysis of peptide bonds. Pepsin, which functions in the stomach to digest proteins, is an example of an aspartic protease; 4) metalloproteases, which require a metal ion, such as zinc, for their catalytic activity. Matrix metalloproteinases (MMPs) are a prominent group of metalloproteases involved in extracellular matrix remodelling and tissue repair. We offer a comprehensive product range of research tools for studying proteolytic enzymes, including NAPSIN A antibodies, alpha 1 Antichymotrypsin antibodies, MMP9 antibodies, MMP9 ELISA Kits, and MMP3 ELISA Kits. Explore our full proteolytic enzymes product range below and discover more, for less. Alternatively, you can explore our Metalloprotease, Serine Protease, and Cysteine Protease product ranges.