2. Signaling Pathways
  3. Immunology/Inflammation
  4. Cyclophilin
  5. Cyclophilin B Isoform

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][11]. 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][12]. 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:

Cyclophilin B Related Products (6):

Cat. No. Product Name Effect Purity
  • HY-135644
    Rencofilstat
    Rencofilstat (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.
  • HY-151488
    CypD-IN-4
    		Inhibitor
    CypD-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.
  • HY-151487
    CypD-IN-3
    		Inhibitor
    CypD-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.
  • HY-151489
    CypE-IN-1
    		Inhibitor
    CypE-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.
  • HY-173265
    CypB-IN-1
    		Inhibitor
    CypB-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.
  • HY-173013
    TWH106
    		Inhibitor
    TWH106 is an inhibitor for Cyclophilin (Cyp) that exhibits good affinity to CypA and CypB with KD of 53 nM and 139 nM. TWH106 inhibits the replication of HIV and HCV, exhibiting antiviral activity.