CST11 Human

The CST11 gene is located on chromosome 20p11.2, within a locus that contains the majority of the type 2 cystatin genes and pseudogenes . The gene spans three exons, a structure similar to other type 2 cystatin family genes . An alternative transcript, CST11Δ2, which lacks exon 2, has also been identified .

The recombinant human CST11 protein is typically produced with an N-terminal His-tag and corresponds to the amino acids 26-103 of the human protein . It is often expressed in E. coli and purified to a high degree of purity (>90%) using SDS-PAGE .

CST11 is expressed predominantly in the male reproductive tract, specifically in the epididymis . Its expression is androgen-regulated, and the protein is most abundant in the initial segment of the epididymis but is also detected throughout the epididymis and on ejaculated human sperm .

The calculated tertiary structure of CST11 reveals regions corresponding to the protease inhibitory wedge of CST3, suggesting a similar protease inhibitor function . Both the intact and exon 2-deleted forms of CST11 have demonstrated antimicrobial activity, significantly reducing bacterial colony-forming units in E. coli .

Recombinant human CST11 is used in various research applications, including studies on male reproductive biology and the role of cysteine protease inhibitors in different physiological and pathological processes . The protein’s antimicrobial properties also make it a subject of interest in studies related to infection and immunity .

For optimal stability, recombinant human CST11 should be stored at 4°C for short-term use and at -20°C for long-term storage. It is important to avoid freeze-thaw cycles to maintain protein integrity .