The CYP11B1 antibody is designed to target the 11-beta-hydroxylase enzyme, a mitochondrial cytochrome P450 enzyme localized in the zona fasciculata of the adrenal cortex. Monoclonal and polyclonal variants exist, with distinct epitope specificities:
Monoclonal Antibodies: Rat-derived monoclonal clones (e.g., CYP11B1-80) exhibit high specificity for the zona fasciculata, distinguishing them from CYP11B2 antibodies that target aldosterone synthase in the zona glomerulosa . These antibodies are generated using peptide epitopes (e.g., YDLGGAGMVC) conjugated to carrier proteins like thyroglobulin .
Polyclonal Antibodies: Rabbit-derived polyclonal antibodies (e.g., ABIN750823) recognize amino acids 202–251 of the CYP11B1 protein, offering broader epitope coverage .
The antibody is versatile, supporting multiple analytical techniques:
Detects a single band at ~52 kDa, confirming specificity for the mature enzyme .
Dilution range: 1:300–1:5000 for polyclonal ; 1:1,000–1:10,000 for monoclonal .
Zona Fasciculata Staining: Monoclonal antibodies (e.g., CYP11B1-80) label cortisol-producing cells in normal and pathological adrenal tissues .
Double Immunofluorescence: Co-localizes with 17α-hydroxylase, confirming its role in cortisol biosynthesis .
Polyclonal antibodies enable quantification of CYP11B1 in cell lysates (ELISA: 1:500–1:1,000) .
Immunofluorescence applications require lower dilutions (1:50–200) for cell culture or paraffin-embedded sections .
DNA hypomethylation at the CYP11B1 promoter correlates with enzyme overexpression, leading to excessive cortisol production . Methylation analysis of CpG sites (−302/+7 promoter region) revealed significant hypomethylation in CPA compared to normal adrenal tissues .
Mutations in CYP11B1 disrupt enzyme function, causing cortisol deficiency and androgen excess . Antibodies are used to diagnose enzyme deficiency in CAH patients .
Specificity: Monoclonal antibodies (e.g., clone 80-7) do not cross-react with CYP11B2, ensuring accurate detection .
Sensitivity: Western blot detection limits are ~10 ng/lane for purified enzyme .
Limitations: Polyclonal antibodies may exhibit batch variability, necessitating lot-specific optimization .