Beta-defensin 123
experimentalAlso known as: Beta-defensin 23, Defensin, beta 123, DEFB123, Q8N688
Beta-defensin 123 (DEFB123) is an antimicrobial peptide belonging to the beta-defensin family, characterized by a conserved six-cysteine motif forming three disulfide bridges. Its mechanism of action involves disruption of bacterial cell membranes via electrostatic interactions with negatively charged phospholipids, leading to pore formation, membrane permeabilization, and subsequent bacterial lysis. This activity is primarily directed against Gram-positive and Gram-negative bacteria, with potential immunomodulatory roles including chemotaxis and cytokine regulation. Current research on DEFB123 remains at an experimental stage, with only five PubMed-indexed studies available. Key findings indicate its expression in epithelial tissues and its in vitro bactericidal effects against pathogens such as *Escherichia coli* and *Staphylococcus aureus*. Limited data suggest possible synergy with other host defense peptides, but no in vivo efficacy or structural-functional studies have been published. The peptide's role in human disease or therapeutic applications has not been established. Clinical relevance is minimal at this stage, as DEFB123 has not advanced beyond preclinical characterization. Its potential as an antimicrobial agent or immune modulator remains speculative, requiring further validation in infection models and safety assessments. No clinical trials or translational studies are currently reported. For research purposes only — not medical advice.
Key data
MKLLLLTLTVLLLLSQLTPGGTQRCWNLYGKCRYRCSKKERVYVYCINNKMCCVKPKYQPKERWWPFMechanism of action
Has antibacterial activity
Research & studies
rDEFB123 inhibits E. coli, K. pneumoniae, and S. aureus growth.; rDEFB123 enhances macrophage phagocytic activity.; rDEFB123 reduces serum ALT/AST and increases IFN-γ and IgG in infected mice.; rDEFB123 downregulates JNK, TRAF2, TRAF6, MIF, IL-1 genes and p-JNK protein in mouse lungs.
Nonconventional proteases (LysargiNase, GluC) improved peptide diversity and sequence coverage compared to trypsin.; Three PE2 missing proteins were identified: beta-defensin 123 (Q8N688), cancer/testis antigen family 45 member A10 (P0DMU9), and Histone H2A-Bbd type 2/3 (P0C5Z0).; Beta-defensin 123 and Histone H2A-Bbd type 2/3 each had only one unique peptide (9 AA), falling under HPP Guidelines v2.1 exceptions.; Validation included spectrum quality checks, isobaric PTM and SAAV filtering, synthetic peptide verification, and overlapping peptides from different proteases.
All four peptide modifications significantly increased antimicrobial activity against MRSA compared to native bovine beta-defensin 123 (P=0.02).; Conferring a hydrophilic C-terminal tail caused the most significant increase in activity against MRSA, with an LD50 of 3.91 μg/mL.; Increased charge at positively selected sites showed the most significant increase in activity against a non-resistant S. aureus strain (P=0.02).; Informed amino acid modifications can significantly affect peptide specificity and antimicrobial efficacy.
Frequently asked questions
What is Beta-defensin 123?
Beta-defensin 123 (DEFB123) is an antimicrobial peptide belonging to the beta-defensin family, characterized by a conserved six-cysteine motif forming three disulfide bridges. Its mechanism of action involves disruption of bacterial cell membranes via electrostatic interactions with negatively charged phospholipids, le
How does Beta-defensin 123 work?
Has antibacterial activity
What is the research status of Beta-defensin 123?
Beta-defensin 123 is currently classified as experimental, with 5 research references on record. This is for research purposes only and is not medical advice.
What is the molecular weight of Beta-defensin 123?
Beta-defensin 123 has a molecular weight of approximately 8105 g/mol.
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