PPIH Human, His

Cyclophilin-H (PPIH) is a member of the cyclophilin family of peptidyl-prolyl isomerases (PPIases), which are enzymes that catalyze the cis-trans isomerization of proline imidic peptide bonds in oligopeptides. This activity is crucial for protein folding and function. Cyclophilin-H is particularly notable for its role in various cellular processes and its interaction with other proteins.

The human recombinant Cyclophilin-H is typically produced in Escherichia coli (E. coli) as a single, non-glycosylated polypeptide chain. It consists of 186 amino acids, including a 10 amino acid N-terminal His tag . The His tag facilitates purification through affinity chromatography, making it easier to isolate the protein in a highly purified form.

Cyclophilin-H functions as a peptidyl-prolyl isomerase, accelerating the folding of proteins by catalyzing the cis-trans isomerization of proline residues. This activity is essential for the proper folding and function of many proteins. Cyclophilin-H is also involved in the assembly of the spliceosome, a complex responsible for pre-mRNA splicing, which is a critical step in gene expression .

Cyclophilins, including Cyclophilin-H, are known to play roles in various biological processes. They are involved in protein folding, signal transduction, and immune response. Cyclophilin-H, in particular, has been implicated in the regulation of RNA splicing and the formation of the spliceosome . Additionally, cyclophilins are known to interact with the immunosuppressive drug cyclosporin A, which is used to prevent organ transplant rejection .

Recombinant Cyclophilin-H with a His tag is widely used in research to study its structure, function, and interactions with other proteins. It is also used in drug discovery, particularly in the development of inhibitors that target cyclophilin activity. These inhibitors have potential therapeutic applications in diseases where cyclophilins play a critical role, such as viral infections and cancer .