biologia: Serpin

Evidence: 100 • authority: 72

Serpins are a superfamily of proteins with similar structures that were first identified for their protease inhibition activity and are found in all kingdoms of life. The acronym serpin was originally coined because the first serpins to be identified act on chymotrypsin-like serine proteases (serine protease inhibitors). They are notable for their unusual mechanism of action, in which they irreversibly inhibit their target protease by undergoing a large conformational change to disrupt the target's active site. This contrasts with the more common competitive mechanism for protease inhibitors that bind to and block access to the protease active site. Protease inhibition by serpins controls a…

Evidence: 53 • authority: 88

Preventing serpin aggregation: The molecular mechanism of citrate action upon antitrypsin unfolding. Abstract The aggregation of antitrypsin into polymers is one of the causes of neonatal hepatitis, cirrhosis, and emphysema. A similar reaction resulting in disease can occur in other human serpins, and collectively they are known as the serpinopathies. One possible therapeutic strategy involves inhibiting the conformational changes involved in antitrypsin aggregation. The citrate ion has previously been shown to prevent antitrypsin aggregation and maintain the protein in an active conformation; its mechanism of action, however, is unknown. Here we demonstrate that the citrate ion prevents th…

Evidence: 36 • authority: 92

The Serpin Superfamily in Adipose Tissue Remodeling: Molecular Drivers of Immune-Metabolic Crosstalk and Insulin Sensitivity.. Adipose tissue remodeling is a dynamic process essential for metabolic homeostasis, enabling tissue expansion, extracellular matrix (ECM) turnover, angiogenesis, and coordinated immune adaptation. In obesity, however, maladaptive remodeling characterized by fibrosis, chronic low-grade inflammation, and hypoxia disrupts adipose plasticity and promotes systemic insulin resistance. Central to these processes is the tightly regulated homeostasis between proteases and their inhibitors, in which the serine protease inhibitor (serpin) superfamily represents an important ye…

Evidence: — • authority: 72

Serine proteases (or serine endopeptidases) are enzymes that cleave peptide bonds in proteins. Serine serves as the nucleophilic amino acid at the enzyme's active site. They are found ubiquitously in both eukaryotes and prokaryotes. Serine proteases fall into two broad categories based on their structure: chymotrypsin-like (trypsin-like) or subtilisin-like.

Evidence: — • authority: 72

An enzyme inhibitor is a molecule that binds to an enzyme and blocks its activity. Enzymes are proteins that speed up chemical reactions necessary for life, in which substrate molecules are converted into products. An enzyme facilitates a specific chemical reaction by binding the substrate to its active site, a specialized area on the enzyme that accelerates the most difficult step of the reaction. An enzyme inhibitor stops ("inhibits") this process, either by binding to the enzyme's active site (thus preventing the substrate itself from binding) or by binding to another site on the enzyme such that the enzyme's catalysis of the reaction is blocked. Enzyme inhibitors may bind reversibly or…

Evidence: — • authority: 92

Chromosome-Scale Atlas of <i>Ixodes scapularis</i> Serine Protease Inhibitors.. Background/Objectives : Ticks evade host hemostasis and immunity in part by injecting serine protease inhibitors (serpins) into the host during feeding, yet the genomic organization of tick serpins has remained unresolved. To understand how ticks deploy these proteins, there is a need to elucidate their gene structure, arrangement and copy number in the genome. Methods : We annotated the recent Ixodes scapularis chromosome-level assembly and identified all the serpin genes to build a genome-wide atlas of serpin loci identifying the gene structure and duplication patterns. The gene expression of serpi…