Human β-defensin HBD3 binds to immobilized Bla g2 from the German cockroach (Blattella germanica).
Human β-defensin 3 (HBD3) is a small, well-characterized peptide in mucosal secretions with broad antimicrobial activities and diverse innate immune functions. Among these functions is the ability of HBD3 to bind to antigens. In this study, we hypothesize that HBD3 binds to the allergen Bla g2 from the German cockroach (Blattella germanica). The ability of HBD1 (used as a control β-defensin) and HBD3 to bind to Bla g2 and human serum albumin (HSA, used as a control ligand) was assessed using the SensíQ Pioneer surface plasmon resonance (SPR) spectroscopy biosensor system. HBD1 was observed to bind weakly to Bla g2, while HBD3 demonstrated a stronger affinity for the allergen. HBD3 was assessed under two buffer conditions using 0.15 M and 0.3 M NaCl to control the electrostatic attraction of the peptide to the chip surface. The apparent K(D) of HBD3 binding Bla g2 was 5.9±2.1 μM and for binding HSA was 4.2±0.7 μM, respectively. Thus, HBD3, found in mucosal secretions has the ability to bind to allergens like Bla g2 possibly by electrostatic interaction, and may alter the ability of Bla g2 to induce localized allergic and/or inflammatory mucosal responses.
Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA.
Deborah E
DE
Dietrich
SensíQ Technologies Inc., 800 Research Parkway, Suite 100, Oklahoma City, OK 73104, USA.
Aaron D
AD
Martin
Dows Institute for Dental Research, College of Dentistry, The University of Iowa, Iowa City, IA 52242, USA; Department of Periodontics and Dows Institute for Dental Research, N423 DSB, College of Dentistry, The University of Iowa, 801 Newton Road, Iowa City, IA 52242, USA. Electronic address: kim-brogden@uiowa.edu.
Kim A
KA
Brogden
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000378:metabolism*; D020048:Blattellidae / Q000378:metabolism*; D006801:Humans; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D023083:beta-Defensins / Q000378:metabolism*
C422950:DEFB103A protein, human; D023083:beta-Defensins; D016282:Aspartic Acid Endopeptidases; C094699:allergen Bla g 2
Allergen; Bla g2; HBD3; Human β-defensin; Surface plasmon resonance spectroscopy