insulin catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of insulin. [GOC:TermGenie]

Insulin catabolism is a complex process that involves the breakdown of insulin molecules into smaller fragments, ultimately rendering the hormone inactive. This process is essential for maintaining proper blood glucose levels and preventing insulin-induced hypoglycemia. The primary sites of insulin catabolism are the liver and kidneys, although other tissues like the brain and muscles also contribute to a lesser extent.

Insulin degradation commences with the binding of insulin to its receptor on the surface of target cells. This binding triggers internalization of the insulin-receptor complex, leading to its delivery to lysosomes, the cellular organelles responsible for breaking down waste products.

Within lysosomes, a variety of proteases, primarily insulin-degrading enzyme (IDE), cleave the insulin molecule at specific peptide bonds. IDE is a zinc-dependent metalloprotease known to be the primary enzyme responsible for insulin degradation. It cleaves insulin at the A-chain, generating an N-terminal fragment and a C-terminal fragment.

Other proteases, such as cathepsins and elastase, may also contribute to insulin degradation. These enzymes, often located in lysosomes, can cleave insulin at various sites, further breaking down the insulin fragments generated by IDE.

The products of insulin catabolism, the smaller peptides and amino acids, are then either reused by the cell or excreted. This ensures that insulin's biological activity is terminated and that the body's glucose homeostasis is maintained.

Factors affecting insulin catabolism include blood glucose levels, insulin concentrations, and the presence of insulin antibodies. Elevated blood glucose levels increase insulin catabolism, while high insulin levels promote its degradation. Insulin antibodies can interfere with insulin degradation, prolonging the hormone's action.

Insulin catabolism plays a critical role in regulating blood glucose levels and is crucial for maintaining proper metabolic function. Disruptions in this process, as seen in certain disease states, can lead to insulin resistance and hyperglycemia, ultimately increasing the risk for diabetes and other metabolic disorders.'
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Proteins (2)

Compounds (25)