Hepson contains a peptidase S1 domain and an SRCR domain. The SRCR domain is located in the extracellular part of the protein, it is formed primarily by three elements of regular secondary structure: a 12-residue alpha helix, a twisted five-stranded antiparallel beta sheet, and a second, two-stranded, antiparallel sheet. The two beta-sheets lie at roughly right angles to each other, with the helix nestled between the two, adopting an SRCR fold. The exact function of this domain has not been identified, though it probably may serve to orient the protease domain or place it in the vicinity of its substrate.[7]
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Pal P, Xi H, Kaushal R, Sun G, Jin CH, Jin L, Suarez BK, Catalona WJ, Deka R (Sep 2006). "Variants in the HEPSIN gene are associated with prostate cancer in men of European origin". Human Genetics. 120 (2): 187–92. doi:10.1007/s00439-006-0204-3. PMID16783571. S2CID13411333.
Betsunoh H, Mukai S, Akiyama Y, Fukushima T, Minamiguchi N, Hasui Y, Osada Y, Kataoka H (Apr 2007). "Clinical relevance of hepsin and hepatocyte growth factor activator inhibitor type 2 expression in renal cell carcinoma". Cancer Science. 98 (4): 491–8. doi:10.1111/j.1349-7006.2007.00412.x. PMID17309599. S2CID26220332.
PDB gallery
1o5e: Dissecting and Designing Inhibitor Selectivity Determinants at the S1 site Using an Artificial Ala190 Protease (Ala190 uPA)
1o5f: Dissecting and Designing Inhibitor Selectivity Determinants at the S1 site Using an Artificial Ala190 Protease (Ala190 uPA)
1p57: Extracellular domain of human hepsin
1z8g: Crystal structure of the extracellular region of the transmembrane serine protease hepsin with covalently bound preferred substrate.