Sequence 3 letters:

H-Gly-Ile-Ile-Asn-Thr-Leu-Gln-Lys-Tyr-Tyr-Cys-Arg-Val-Arg-Gly-Gly-Arg-Cys-Ala-Val-Leu-Ser-Cys-Leu-Pro-Lys-Glu-Glu-Gln-Ile-Gly-Lys-Cys-Ser-Thr-Arg-Gly-Arg-Lys-Cys-Cys-Arg-Arg-Lys-Lys-OH

Sequence:

H-GIINTLQKYYCRVRGGRCAVLSCLPKEEQIGKCSTRGRKCCRRKK-OH (Disulfide bridge: 11-40, 18-33, 23-41)

Cas No. :

Molecular Formula:

C₂₁₆H₃₇₁N₇₅O₅₉S₆

Molecular Weight:

5155.09

Description

This is a 5.1kDa 45-amino acid antimicrobial peptide called beta-Defensin-3 (hBD-3) having a beta sheet with three intramolecular disulfide bonds. It is expressed in high levels in keratinocytes and tonsilar tissue while expressed low in epithelia of the respiratory, gastrointestinal and genito-urinary tracts. Factors that induce its expression include TNF-alpha, IL-1beta and bacteria such as P. aeruginosa and S. aureus. hBD-3 is also potentially induced after exposure to IFN-gamma. In contrast to hBD-1, -2 and -4, hBD-3 demonstrates a salt-insensitive antimicrobial activity towards several pathogenic microorganisms at physiologic salt concentrations. This makes hBD-3 uniquely and particularly relevant in diseases where other hBDs show inactivity. The ability of hBD-3 to elicit its antimicrobial activity more effectively at the concentrations lower that those of hBD-1 and hBD-2 has been attributed to its amphipathic dimer structure and the increased positive surface charge (+9), compared to hBD-1 (+4) and hBD-2 (+6). hBD-3 has been shown to induce cytokine production from human keratinocytes and stimulates monocyte migration.

Reference

• J. Harder, J. Bartels, E. Christophers, and J.-M. Schröder, J. Biol. Chem., 276, 5707 (2001). (Original);
• L.A. Duits, et al., Biochem. Biophys. Res. Commun., 280, 522 (2001). (Pharmacol.);
• H.P. Jia, et al., Gene, 263, 211 (2001).