Cyclophilin B
Cyclophilin B (CyPB), encoded by PPIB, is an endoplasmic reticulum (ER)-resident peptidyl-prolyl cis-trans isomerase that catalyzes proline isomerization and supports protein folding within the secretory pathway[1][2]. Mechanistically, CyPB functions as a major folding catalyst for type I collagen by accelerating the rate-limiting cis-trans conversion of proline residues required for triple-helix formation[3][4][5]. CyPB also operates within the P3H1/CRTAP/PPIB complex, which is essential for procollagen folding and prolyl 3-hydroxylation in the ER, linking its enzymatic activity to collagen biosynthesis and extracellular matrix assembly[6][7]. In disease models, PPIB deficiency disrupts collagen post-translational modification, delays procollagen folding, alters collagen cross-linking, and causes recessive osteogenesis imperfecta with defective connective tissue formation[8][9][10][2]. Compared with other rough ER-resident peptidyl-prolyl isomerases, CyPB has a particularly prominent role in collagen maturation because collagen molecules contain abundant proline residues that require efficient isomerization during biosynthesis[5][11]. Structural and biochemical studies further demonstrate that CyPB interacts with calnexin-associated folding machinery and collagen-processing complexes, highlighting its specialized ER chaperone function rather than a generalized folding role[2][6]. For experimental applications, cyclosporin A binds the active site of CyPB and inhibits its isomerase activity, providing a widely used pharmacological tool for investigating collagen folding, ER protein maturation, and connective tissue biology[2][4].
References:
- [1]. Cyclophilin B gene information from NCBI.
- [2]. Lee MJ, et al. Time to HIV rebound after infusion of long-acting broadly neutralising antibodies 3BNC117-LS and 10-1074-LS and analytical treatment interruption (the RIO trial): a double-blind, randomised, placebo-controlled trial. Lancet HIV. 2026 May 27:S2352-3018(26)00059-7. [Content Brief]
- [3]. Li W, et al. The structural basis for the collagen processing by human P3H1/CRTAP/PPIB ternary complex. Nat Commun. 2024 Sep 8;15(1):7844. [Content Brief]
- [4]. Ishikawa Y, et al. Ziploc-ing the structure: Triple helix formation is coordinated by rough endoplasmic reticulum resident PPIases. Biochim Biophys Acta. 2015 Oct;1850(10):1983-93. [Content Brief]
- [5]. Cabral WA, et al. Abnormal type I collagen post-translational modification and crosslinking in a cyclophilin B KO mouse model of recessive osteogenesis imperfecta. PLoS Genet. 2014 Jun 26;10(6):e1004465. [Content Brief]
- [6]. Wu J, et al. Characterization of PPIB interaction in the P3H1 ternary complex and implications for its pathological mutations. Cell Mol Life Sci. 2019 Oct;76(19):3899-3914. [Content Brief]
- [7]. Kiros M, et al. Trends in HIV-1 pretreatment drug resistance and HIV-1 variant dynamics among antiretroviral therapy-naive Ethiopians from 2003 to 2018: a pooled sequence analysis. Virol J. 2023 Oct 25;20(1):243. [Content Brief]
- [8]. Okada Y, et al. Genome-wide association study for C-reactive protein levels identified pleiotropic associations in the IL6 locus. Hum Mol Genet. 2011 Mar 15;20(6):1224-31. [Content Brief]
- [9]. Barnes AM, et al. Lack of cyclophilin B in osteogenesis imperfecta with normal collagen folding. N Engl J Med. 2010 Feb 11;362(6):521-8. [Content Brief]
- [10]. Rabezanahary H, et al. Live virus neutralizing antibodies against pre and post Omicron strains in food and retail workers in Québec, Canada. Heliyon. 2024 May 21;10(10):e31026. [Content Brief]
- [11]. Koag MC, et al. Structural basis for the inefficient nucleotide incorporation opposite cisplatin-DNA lesion by human DNA polymerase β. J Biol Chem. 2014 Nov 7;289(45):31341-8. [Content Brief]
All Product Categories
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Cyclophilin B Related Products (6)
Related Products (6)
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Rencofilstat
0 ImagesCat. No.: HY-135644CAS No.: 1383420-08-3Synonyms: CRV431Rencofilstat (CRV431) is an orally active pan-cyclophilin inhibitor with IC50 values of 2.5 nM, 3.1 nM, 2.8 nM, 7.3 nM for Cyp A, CypB, Cyp D and Cyp G, respectively. Rencofilstat reduces fibrosis and tumor growth in models of chronic liver disease. Rencofilstat can be used for the study of nonalcoholic steatohepatitis (NASH), hepatocellular carcinoma and viral hepatitis-induced liver disease.
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CypD-IN-4
0 ImagesCat. No.: HY-151488CAS No.: 3023438-19-6CypD-IN-4 is a potent and subtype-selective cyclophilin D (CypD) inhibitor. CypD-IN-4 has CypD affinity with an IC50 value of 0.057 μM. CypD-IN-4 can be used for the research of several diseases including oxidative stress, neurodegenerative disorders, liver diseases, aging, autophagy and diabetes.
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CypD-IN-3
0 ImagesCat. No.: HY-151487CAS No.: 2651994-75-9CypD-IN-3 is a potent and subtype-selective cyclophilin D (CypD) inhibitor. CypD-IN-3 has CypD affinity with an IC50 value of 0.01 μM. CypD-IN-3 can be used for the research of several diseases including oxidative stress, neurodegenerative disorders, liver diseases, aging, autophagy and diabetes.
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CypE-IN-1
0 ImagesCat. No.: HY-151489CAS No.: 3023438-33-4CypE-IN-1 is a potent and subtype-selective cyclophilin E (CypE) inhibitor. CypE-IN-1 has CypE affinity with IC50 and Ki values of 0.013 μM and 0.072 μM, respectively. CypE-IN-1 can be used for the research of several diseases including oxidative stress, neurodegenerative disorders, liver diseases, aging, autophagy and diabetes.
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CypB-IN-1
0 ImagesCat. No.: HY-173265CypB-IN-1 (Compound 11) is an inhibitor of cyclophilin B (cyclophilin B) with a Kd value of 12 nM. CypB-IN-1 can be applied to the research field of metabolic dysfunction-associated steatohepatitis (MASH) and the liver fibrosis diseases resulting from it.
