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At least 19 recordsLinked to original sources
PubMed2003

Messenger RNA (mRNA) expression for the antimicrobial peptides beta-defensin-1 and beta-defensin-2 in the male rat reproductive tract: beta-defensin-1 mRNA in initial segment and caput epididymidis is regulated by androgens and not bacterial lipopolysaccharides.

Mechanisms of antimicrobial protection in male reproductive organs are poorly understood. Defensins are antimicrobial peptides produced by many epithelial tissues. The goals of the present study were 1). to test the hypothesis that adult rat male reproductive organs express mRNA for rat beta-defensin (RBD)-1 and RBD-2, 2). to examine if defensin mRNA expression in the testis and epididymis is induced by bacterial lipopolysaccharides (LPS), and 3). to investigate the effects of androgens on defensin mRNA expression in the epididymis. Total RNA from reproductive organs was analyzed by relative reverse transcription-polymerase chain reaction analysis. RBD-1 mRNA was detected in the testis. All segments of epididymis expressed equal levels of RBD-1 mRNA with higher expression than in the testis, whereas accessory sex glands showed expression equal to that in the testis. Expression of RBD-2 mRNA was primarily restricted to the penis. Effects of inflammation on defensin mRNA expression were examined in rats administered a unilateral injection of LPS from Pseudomonas aeruginosa or Escherichia coli. Expression of RBD-1 mRNA in the testis and epididymis was unaffected by LPS. To test the hypothesis that circulating androgens regulate RBD-1 mRNA expression in the epididymis, rats were subjected to bilateral orchiectomy (orch) or to orch plus a 3.5-cm implant containing testosterone. Expression of RBD-1 mRNA in the initial segment and caput was unchanged following 1-day orch but showed androgen-sensitive expression after 5 and 15 days. Expression of RBD-1 mRNA in corpus and cauda was not affected by orch. Results of this study suggest that RBD-1 may play an antimicrobial role in the testis and epididymis.

Androgens↗
PubMed1995

Solution structure of bovine neutrophil beta-defensin-12: the peptide fold of the beta-defensins is identical to that of the classical defensins.

The solution structure is reported for bovine neutrophil beta-defensin-12 (BNBD-12), a member of the beta-defensin family of antimicrobial peptides. Structural constraints in the form of proton-proton distances, dihedral angles, and hydrogen bond constraints were derived from two-dimensional, homonuclear magnetic resonance spectroscopy experiments. The three-dimensional structure of BNBD-12 was calculated using distance geometry and restrained molecular dynamics. An ensemble of structures with low NOE constraint violation energies revealed a precisely defined triple-stranded, antiparallel beta-sheet as the structural core of the peptide. The N-terminal beta-strand and three locally well-defined tight turns form a hydrophobic face. Conserved isoleucine and glycine residues form a beta-bulge structure which initiates a beta-hairpin secondary structure motif composed of the second and C-terminal beta-strands. The beta-hairpin contains numerous charged residues and forms the cationic face of BNBD-12. The N-terminal residues were found to be disordered, due to an absence of tertiary NOEs. The triple-stranded beta-sheet, the beta-bulge preceding the hairpin, and the cationic/hydrophobic amphiphilic character are definitive features of all defensin structures determined to date. Further, we predict that the tracheal antimicrobial peptide (TAP) and the recently described gallinacins will have tertiary structures similar to that of BNBD-12.

Amino Acid Sequence↗
PubMed2003

From pro defensins to defensins: synthesis and characterization of human neutrophil pro alpha-defensin-1 and its mature domain.

Human neutrophil alpha-defensins (HNPs) are small, cationic, Cys-rich antimicrobial proteins that play important roles in innate immunity against infectious microbes such as bacteria, fungi and enveloped viruses. Synthesized as inactive precursors in vivo (pre-proHNPs), HNPs are activated through proteolytic removal of the inhibitory pro-peptide required for subcellular sorting and correct folding. We seek to understand the molecular basis for the recognition between the 45-residue pro-peptide and the C-terminal functional domain. Here we described, total chemical synthesis of the 75-residue human neutrophil pro alpha-defensin-1 (proHNP1) via native chemical ligation. After oxidative folding, proHNP1 is cleaved by cyanogen bromide at the Met45-Ala46 peptide bond to release the mature form. The native disulfide connectivity in HNP1, i.e. Cys1-Cys6, Cys2-Cys4 and Cys3-Cys5, is verified by mass mapping of peptide fragments generated by proteolytic digestion and Edman degradation. Fluorescence spectroscopy studies and antimicrobial activity assays further support that synthetic proHNP1 and HNP1 are correctly folded. While largely unstructured in aqueous solution, the pro-peptide binds to HNP1 intermolecularly with an apparent Kd value of 6.2 microM at pH 7.4, confirming the mode of intramolecular inactivation of human alpha-defensin precursors.

Amino Acid Sequence↗
PubMed2004

A genome-wide screen identifies a single beta-defensin gene cluster in the chicken: implications for the origin and evolution of mammalian defensins.

BACKGROUND: Defensins comprise a large family of cationic antimicrobial peptides that are characterized by the presence of a conserved cysteine-rich defensin motif. Based on the spacing pattern of cysteines, these defensins are broadly divided into five groups, namely plant, invertebrate, alpha-, beta-, and theta-defensins, with the last three groups being mostly found in mammalian species. However, the evolutionary relationships among these five groups of defensins remain controversial. RESULTS: Following a comprehensive screen, here we report that the chicken genome encodes a total of 13 different beta-defensins but with no other groups of defensins being discovered. These chicken beta-defensin genes, designated as Gallinacin 1-13, are clustered densely within a 86-Kb distance on the chromosome 3q3.5-q3.7. The deduced peptides vary from 63 to 104 amino acid residues in length sharing the characteristic defensin motif. Based on the tissue expression pattern, 13 beta-defensin genes can be divided into two subgroups with Gallinacin 1-7 being predominantly expressed in bone marrow and the respiratory tract and the remaining genes being restricted to liver and the urogenital tract. Comparative analysis of the defensin clusters among chicken, mouse, and human suggested that vertebrate defensins have evolved from a single beta-defensin-like gene, which has undergone rapid duplication, diversification, and translocation in various vertebrate lineages during evolution. CONCLUSIONS: We conclude that the chicken genome encodes only beta-defensin sequences and that all mammalian defensins are evolved from a common beta-defensin-like ancestor. The alpha-defensins arose from beta-defensins by gene duplication, which may have occurred after the divergence of mammals from other vertebrates, and theta-defensins have arisen from alpha-defensins specific to the primate lineage. Further analysis of these defensins in different vertebrate lineages will shed light on the mechanisms of host defense and evolution of innate immunity.

Amino Acid Motifs↗
PubMed2005

Two structurally different defensin genes, one of them encoding a novel defensin isoform, are expressed in honeybee Apis mellifera.

Two defensins showing high mutual similarity have previously been characterized in honeybee Apis mellifera: royalisin, a peptide isolated from the royal jelly, and defensin, found in the hemolymph of bacterially infected bees. Here we show that both these peptides are encoded by the same polymorphic gene, which we termed defensin1. Besides this gene, we identified an additional defensin gene coding for a novel honeybee defensin designated defensin2. The pre-pro-peptide sequence of defensin 2 was inferred from its cDNA. Mature defensin 2 peptide shows 55.8% identity with defensin 1. Sequences of genomic loci of the two defensin genes revealed their different structure. Defensin1 possesses an exon-intron structure unique among arthropoda defensin genes. Its second intron splits exactly the common structural module of defensins from a short amidated C-terminal extension found only in hymenopteran defensins. Transcription of defensin genes in some nurse honeybees tissues was studied by RT-PCR. Both defensins are expressed in heads and thoraces. Defensin1 but not defensin2 mRNA was detected in hyphopharyngeal, mandibular and thoracic salivary glands. Immune response elements were identified by computer analysis of the promoter regions of defensin genes. Their different representation in these genes reflects presumably observed tissue-specific expression of defensins.

Amino Acid Sequence↗
PubMed2004

Theta-defensins: cyclic antimicrobial peptides produced by binary ligation of truncated alpha-defensins.

The first cyclic peptide discovered in animals is an antimicrobial octadecapeptide that is expressed in leukocytes of rhesus monkeys. The peptide, termed rhesus Theta-defensin 1 (RTD-1) is the prototype of a new family of antimicrobial peptides, which like the previously characterized alpha- and beta-defensin families, possesses broad spectrum microbicidal activities against bacteria, fungi, and protects mononuclear cells from infection by HIV-1. The cyclic Theta-defensin structure is essential for a number of its antimicrobial properties, as demonstrated by the markedly reduced microbicidal activities of de-cyclized Theta-defensin analogs. Genetic and biochemical experiments disclosed that the biosynthesis of RTD-1 results from the head-to-tail joining of two nine-amino acid peptides, each of which is donated by a separate precursor polypeptide, which are in fact C-terminally truncated pro-alpha-defensins. Alternate combinations of the two nonapeptides generate two additional macaque Theta-defensins, RTD-2 and RTD-3. Humans do not express Theta-defensin peptides, but mRNAs encoding at least two Theta-defensins are expressed in human bone marrow. However, in each case the open reading frame is interrupted by a stop codon in the signal peptide-coding region. The mature Theta-defensin peptide is a two-stranded beta-sheet that, like the alpha- and beta-defensins, is stabilized by three disulfides. However, the parallel orientation of the Theta-defensin disulfide arrangement allows for substantial flexibility around its short axis. Unlike alpha- and beta-defensins, RTD-1 lacks an amphiphilic topology. This may partially explain the unusual interaction between Theta-defensins and phospholipid bilayers.

Amino Acid Sequence↗
PubMed1996

Interactions of monomeric rabbit neutrophil defensins with bilayers: comparison with dimeric human defensin HNP-2.

Human antimicrobial neutrophil defensin HNP-2 has been shown to form large multimeric pores in pure 1-palmitoyl-2-oleoyl phosphatidylglycerol (POPG) bilayers that lead to all-or-none release of vesicle contents [Wimley et al. (1994) Protein Sci.3, 1362-1373]. Because human neutrophil defensins form natural dimers in solution, the question arises as to the role of dimerization in pore formation. However, the dimers are so stable that this question is not easily answered directly. Rabbit neutrophil defensins, whose three-dimensional structures are very similar to those of human defensins, are monomeric in aqueous solution and thus provide an opportunity to test the hypothesis that dimerization may play a role in multimeric pore formation. We therefore examined the interactions of the six known rabbit neutrophil defensins with large unilamellar vesicles (LUV) under the conditions known to lead to stable pore formation by HNP-2. We find that the rabbit defensins bind strongly to LUVs formed from pure POPG or mixtures of POPG with neutral (zwitterionic) phospholipid but induce leakage of vesicle contents only from pure POPG vesicles. Rabbit defensin NP-4 does not cause leakage under any conditions examined. The remaining defensins, NP-1, NP-2, NP-3A, NP-3B, and NP-5, cause graded release of the contents of pure POPG vesicles as does a mixture of the six defensins. The graded release indicates that the rabbit defensins do not form stable pores in the membrane. This result thus suggests that the structural features of human defensins that permit dimer formation in aqueous solution are likely to be important in the formation of multimeric pores.

Amino Acid Sequence↗
PubMed2004

Bovine beta-defensins: identification and characterization of novel bovine beta-defensin genes and their expression in mammary gland tissue.

beta-Defensin genes code for multifunctional peptides with a broad-range antimicrobial activity. In this project we hypothesized that beta-defensin genes may be candidate genes for resistance to mastitis. In this article we describe the identification and genomic characterization of eight bovine beta-defensin genes, including six novel defensin genes and two pseudogenes. Expression in the bovine mammary gland of one of the novel genes, DEFB401, has been demonstrated, as well as the expression of LAP, TAP, DEFB1, BNBD3, BNBD9, and BNBD12. For genomic characterization, 20 BACs from two different bovine BAC libraries (RZPD numbers 750 and 754) were isolated by PCR screening with beta-defensin consensus primers derived from published sequences. PCR products from BACs generated with consensus primers have been subcloned and sequenced, revealing a total of 16 genes and two pseudogenes. Six novel beta-defensin genes share the typical exon-intron structure and are highly homologous to published bovine beta-defensin genes. They are named DEFB401- DEFB405 and LAP-like, and two novel pseudogenes are named EBD-P and EBD-P2. Analysis of mammary gland tissue-derived cDNA from nine cows with different clinical findings demonstrated the expression of several beta-defensin genes mentioned above. First results indicate that the lactational status of the cow presumably has no influence on gene expression. Competent knowledge of antimicrobial activity of beta-defensins from literature, the abundance of beta-defensin mRNA in the bovine mammary gland, and the inducibility of some genes give first evidence that beta-defensins may play a role in local host defense during udder infections.

Amino Acid Sequence↗
PubMed1998

Mouse beta defensin-1 is a functional homolog of human beta defensin-1.

Defensin are 3-4 kDa antimicrobial peptides of which three distinct families have been identified; alpha-defensin, beta-defensins, and insect defensins. Recent investigations have shown that beta-defensins are present in the human airways and may be relevant to the pathogenesis of cystic fibrosis (CF) lung disease. We report here the further characterization of a recently identified mouse beta-defensin gene, Defb1, sometimes referred to as mBD-1, which is homologous to the human airway beta defensin hBD-1. We report that Defb1 is expressed in a variety of tissues including the airways and, similar to hBD-1, is not upregulated by lipopolysaccharide (LPS). Defb1 was found to consist of two small exons separated by a 16-kb intron and cytogenetic, and physical mapping linked it to the alpha defensin gene cluster on mouse Chromosome (Chr) 8. Functional studies demonstrate that, like hBD-1, Defb1 demonstrates a salt-sensitive antimicrobial activity against Pseudomonas aeruginosa. Of relevance to CF lung disease is the fact that neither the hBD-1 nor the mBD-1 peptides are active against Burkholderia cepacia.

Amino Acid Sequence↗
PubMed2001

Expression of the peptide antibiotics human beta defensin-1 and human beta defensin-2 in normal human skin.

Normal human skin is remarkably resistant to infection from the large numbers of microorganisms that routinely colonize its surface. In addition to the role of skin as a mechanical barrier, it has long been recognized that skin and other epithelia can produce a range of anti-microbial chemicals that play an important part in eliminating potential cutaneous pathogens. Anti-microbial peptides are an important evolutionarily conserved innate host defense mechanism in many organisms. Human beta defensin-1 and -2 are cysteine-rich, cationic, low molecular weight anti-microbial peptides that have recently been shown to be expressed in epithelial tissues. In this study, we describe the characterization of human beta defensin-1 and -2 mRNA and peptide expression in normal human skin. Using reverse transcription-polymerase chain reaction we demonstrate that human beta defensin-1 is consistently expressed in skin samples from various body sites. Human beta defensin-2 demonstrates expression that is more variable and is more readily detectable in facial skin and foreskin compared with skin from abdomen and breast. In situ hybridization localizes the human beta defensin-1 and -2 transcripts to keratinocytes within interfollicular skin. Using specific antibodies, we have shown that human beta defensin-1 and -2 peptides are localized to the Malpighian layer of the epidermis and/or stratum corneum and that there are interindividual and site-specific differences in intensity of immunostaining and the pattern of peptide localization. The localization of human beta defensins to the outer layer of the skin is consistent with the hypothesis that human beta defensins play an essential part in cutaneous innate immunity.

3T3 Cells↗
PubMed1992

Bactericidal activities of rat defensins and synthetic rabbit defensins on Staphylococci, Klebsiella pneumoniae (Chedid, 277, and 8N3), Pseudomonas aeruginosa (mucoid and nonmucoid strains), Salmonella typhimurium (Ra, Rc, Rd, and Re of LPS mutants) and Escherichia coli.

Rat defensins were purified and tested for in vitro bactericidal assay against gram-positive and gram-negative bacteria. Staphylococcus aureus (209P, Cowan I, Smith diffuse and Smith compact) were resistant to defensins, whereas Staphylococcus epidermidis, Staphylococcus saprophyticus, Micrococcus lysodeikticus and Bacillus subtilis were less sensitive. Gram-negative bacteria, such as Pseudomonas aeruginosa (mucoid and K) and Klebsiella pneumoniae (Chedid, 277, and 8N3 which were heavily capsulated, moderately capsulated and noncapsulated, respectively) were all very sensitive to defensins and killed within 20 min. Escherichia coli was moderately sensitive and the rough mutants of lipopolysaccharide (LPS) of Salmonella typhimurium LT2, such as Ra, Rc, Rd, and Re were equally sensitive to defensins, being killed within 40 min. Lysozyme did not show any bactericidal activity except against M. lysodeikticus and B. subtilis, whereas it enhanced the bactericidal activity of defensins against P. aeruginosa, E. coli, and K. pneumoniae and suppressed the killing activity of defensins against S. typhimurium and S. aureus. With regard to the three synthetic rabbit defensins, NP1, NP4, and NP5, NP1 showed strong bactericidal activity against K. pneumoniae 277, comparable to that of rat defensins. Neither NP4 nor NP5 showed any bactericidal activity, while NP5 rather enhanced the bactericidal activity of NP1 against K. pneumoniae 277.

Animals↗
PubMed1996

Identification of defensin-1, defensin-2, and CAP37/azurocidin as T-cell chemoattractant proteins released from interleukin-8-stimulated neutrophils.

Reports that interleukin-8 (IL-8) induces the infiltration of neutrophils followed by T-cells into injection sites led us to postulate that by stimulation of neutrophil degranulation IL-8 may cause the release of factors with chemoattractant activity for T-lymphocytes. Extracts of human neutrophil granules were chromatographed to isolate and purify T-lymphocyte chemoattractant factors. Two major peaks of T-cell chemotactic activity were purified by C18 reversed phase high pressure liquid chromatography (HPLC). The first peak was resolved further by C4 reversed phase HPLC and yielded an active fraction shown by NH2-terminal amino acid sequence analysis to contain defensins HNP-1, HNP-2, and HNP-3. Purified defensins HNP-1 and HNP-2 (kindly provided by Dr. R. I. Lehrer, UCLA) were also potent chemoattractants for human T-cells, while HNP-3 was inactive. The second peak of T-cell chemoattractant activity was also further purified to homogeneity by C4 reversed phase HPLC and identified by NH2-terminal sequence analysis as CAP37/azurocidin, a protein with sequence homology to serine proteases. 0.1 100 ng of defensins and 1.0 100 ng/ml CAP37 were able to stimulate in vitro T-cell chemotaxis. Neutrophil activating factors, i.e. IL-8, phorbol 12-myristate 13-acetate/ionomycin, and formylmethionylleucylphenylalanine each induced the release of CAP37 and defensins from neutrophil granules. Subcutaneous administration of defensins or CAP37/azurocidin into BALB/c mice resulted in a moderate neutrophil and mononuclear cell infiltrate by 4 h, which was greater by 24 h at the site of injection. Additionally, subcutaneous injection of defensins into chimeric huPBL-SCID mice resulted in significant infiltration by human CD3+ cells within 4 h. These results identify the antimicrobial proteins, CAP37/azurocidin and defensins HNP-1 and HNP-2, as potent neutrophil-derived chemoattractants for T-cells. These proteins represent primordial antimicrobial peptides which may have evolved into acute inflammatory cell-derived signals that mobilize immunocompetent T-cells and other inflammatory cells.

Amino Acid Sequence↗
PubMed2006

A putative novel role for plant defensins: a defensin from the zinc hyper-accumulating plant, Arabidopsis halleri, confers zinc tolerance.

The metal tolerance of metal hyper-accumulating plants is a poorly understood mechanism. In order to unravel the molecular basis of zinc (Zn) tolerance in the Zn hyper-accumulating plant Arabidopsis halleri ssp. halleri, we carried out a functional screening of an A. halleri cDNA library in the yeast Saccharomyces cerevisiae to search for genes conferring Zn tolerance to yeast cells. The screening revealed four A. halleri defensin genes (AhPDFs), which induced Zn but not cadmium (Cd) tolerance in yeast. The expression of AhPDF1.1 under the control of the 35S promoter in A. thaliana made the transgenic plants more tolerant to Zn than wild-type plants, but did not change the tolerance to Cd, copper (Cu), cobalt (Co), iron (Fe) or sodium (Na). Thus, AhPDF1.1 is able to confer Zn tolerance both to yeast and plants. In A. halleri, defensins are constitutively accumulated at a higher level in shoots than in A. thaliana. A. halleri defensin pools are Zn-responsive, both at the mRNA and protein levels. In A. thaliana, some but not all defensin genes are induced by ZnCl2 treatment, and these genes are not induced by NaCl treatment. Defensins, found in a very large number of organisms, are known to be involved in the innate immune system but have never been found to play any role in metal physiology. Our results support the proposition that defensins could be involved in Zn tolerance in A. halleri, and that a role for plant defensins in metal physiology should be considered.

Amino Acid Sequence↗
PubMed1993

Purification and characterization of a scorpion defensin, a 4kDa antibacterial peptide presenting structural similarities with insect defensins and scorpion toxins.

Insect defensins are a group of inducible small-sized antibacterial peptides with three intramolecular disulfide bridges. NMR studies have recently shown that they share striking structural similarities with scorpion toxins. We have investigated in a scorpion species, Leiurus quinquestriatus, the potential presence of antibacterial molecules and report the isolation and structural characterization of a novel insect defensin homologue, which we refer to as scorpion defensin. This peptide shows a remarkably high degree of sequence homology with a defensin recently characterized in a species belonging to the ancient insect order of the Odonata with which it defines a novel ancient subclass of defensins. The scorpion defensin has in common with the scorpion toxins a consensus sequence Cys-[...]-Cys-Xaa-Xaa-Xaa-Cys-[...]-Gly-Xaa-Cys-[...]-Cys-Xaa-Cys present in all scorpion toxins characterized so far.

Amino Acid Sequence↗
PubMed1997

Penetration of the insect defensin A into phospholipid monolayers and formation of defensin A-lipid complexes.

Defensin A is an inducible cationic protein secreted in the hemolymph of fleshfly Phormia terranovae larvae in response to bacterial or septic injuries. Defensin A is known to permeabilize the bacteria cell membranes by forming voltage-dependent channels. The penetration of this small protein into lipid monolayers was studied as a function of the polar head and acyl chain length of phospholipids. The extent of penetration by defensin A is higher in monolayers made of anionic phospholipids than in monolayers made of zwitterionic phospholipids (phosphatidylcholines), because of electrostatic interactions. From the analysis of the compression isotherm parameters of mixed defensin A/phospholipid monolayers, it appears that defensin A interacts with phospholipid by forming 1:4 complexes. These complexes are not miscible in the lipid phase and induce microheterogeneity in the lipid membrane. These clusters might be related to the ion-channel structures responsible for the biological activity of defensin A.

Animals↗
PubMed1999

Immunity proteins from mosquito cell lines include three defensin A isoforms from Aedes aegypti and a defensin D from Aedes albopictus.

An Aedes aegypti mosquito cell line, Aag-2, exhibits a response to immune stimulation that is qualitatively similar to that of C7-10 cultured cells from the related mosquito, Aedes albopictus. Using SDS polyacrylamide gels, we found that a small peptide was preferentially induced by the treatment of growing cells with heat-killed, Gram-positive bacteria. By an analogy with other studies, this small peptide was postulated to be a member of the defensin family of insect immunity peptides. A differential display was used to obtain partial polymerase chain reaction products corresponding to mRNAs that were preferentially expressed in induced cells. One of these products, which contained the partial sequence of a defensin gene, was used to screen cDNA libraries from Ae. aegypti and Ae. albopictus cells. From Ae. aegypti cells, we found two previously described isoforms (A1 and A4) of mosquito defensin A, as well as a new isoform which we defined as A5. From Ae. albopictus cells, we found a new mature mosquito defensin, named D, which contains proline and isoleucine as the final amino acids. In both Ae. aegypti and Ae. albopictus cell lines, the expression of defensin mRNA was visible on Northern blots as early as 3 h after exposure to heat-killed bacteria, and defensin mRNA abundance was maximal at 12-36 h after induction.

Aedes↗
PubMed2001

The structure of human beta-defensin-1: new insights into structural properties of beta-defensins.

Defensins are a class of small cationic peptides found in higher organisms that serve as both antimicrobial and cell signaling molecules. The exact mechanism of the antimicrobial activity of defensins is not known, but two models have been postulated, one involving pore formation and the other involving nonspecific electrostatic interaction with the bacterial membrane. Here we report the high resolution structures of human beta-defensin-1 (hBD1) in two crystallographic space groups. The structure of a single molecule is very similar to that of human beta-defensin-2 (hBD2), confirming the presence of an N-terminal alpha-helix. However, while the packing of hBD1 is conserved across both space groups, there is no evidence for any larger quaternary structure similar to octameric hBD2. Furthermore, the topology of hBD1 dimers that are formed between monomers in the asymmetric unit is distinct from both hBD2 and other mammalian alpha-defensins. The structures of hBD1 and hBD2 provide a first step toward understanding the structural basis of antimicrobial and chemotactic properties of human beta-defensins.

Amino Acid Sequence↗
PubMed2006

Defensins knowledgebase: a manually curated database and information source focused on the defensins family of antimicrobial peptides.

The defensins knowledgebase is a manually curated database and information source focused on the defensin family of antimicrobial peptides. The current version of the database holds a comprehensive collection of over 350 defensin records each containing sequence, structure and activity information. A web-based interface provides access to the information and allows for text-based searching on the data fields. In addition, the website presents information on patents, grants, research laboratories and scientists, clinical studies and commercial entities pertaining to defensins. With the rapidly increasing interest in defensins, we hope that the knowledgebase will prove to be a valuable resource in the field of antimicrobial peptide research. The defensins knowledgebase is available at http://defensins.bii.a-star.edu.sg/.

Anti-Bacterial Agents↗