Of defensins

Ashitani, J., et al., Elevated concentrations of defensins in bronchoalveolar lavage fluid in diffuse panbronchiolitis, Eur. Respir. J. 11, 1, 104, 1998. 

The mechanism of action of defensins is largely unknown. Incubation with defensins results in the formation of voltage-regulated ion channels that permeabilise the outer and inner membranes of metabolically-active E. coli. Because the target bacteria must be metabolically active for defensins to exert their effects, it may be that the transmembrane electromotive force is involved in the mechanism of action. 

Valore, E. V., Ganz, T. (1992). Posttranslational processing of defensins in immature human myeloid cells. Blood 79,1538-44. 

Gonzales, M., Gueguen, Y., Desserre, G., de Lorgeril, J., Romestand, B., and Bachere, E. (2007). Molecular characterization of two isoforms of defensin from hemocytes of the oyster Crassostrea gigas. Dev. Comp. Immunol. 31,332-339. 

Figure 31-7 Ribbon structures of some defensins. (A) Structure of a human fl-defensin showing the three disulfide bonds. From Bauer et al.134 Courtesy of Heinrich Sticht. (B) Comparison of the folding patterns of four types of defensins. Mammalian a- and P-defensins are all P sheets with somewhat different arrangements of disulfide bridges. Insect and plant defensins have an a helix joined to the P sheet. Mammalian and insect defensins have three disulfide bridges, while plant defensins have four. From Hoffmann et al.12 Courtesy of Jules A. Hoffmann.

Nam MJ, Kee MK, Kuick R, Hanash SM. Identification of defensin alpha6 as a potential biomarker in colon adenocarcinoma. J Biol Chem 2005 280(9) 8260-8265. 

In Omithodoros ticks, the peptide defensin A and three isoforms of defensin were recorded to be secreted into the midgut lumen and, therefore, provide midgut defense.109... 

Territo, M.C., Ganz, T., Selsted, M.E. and Lehrer, KI. (1989). Monocyte chemotactic activity of defensins from human neutrophils. J. Clin. Invest. 84, 2017-2020. 

Defensins are variably cationic, relatively arginine-rich, nonglycosylated peptides comprised of 29-34 amino acid residues. Human (HNP-1) and rabbit (NP-5) defensins have been studied by NMR techniques and showed that they are rich in beta sheet structure. Although both types of defensins permeabilize the outer membrane of E. coli [31], they differ from other peptides with similar action but rich in alpha helices such as magainin, mellitin and cecropin. 

Chertov O, Michiel DF, Xu L, Wang JM, Tani K, Murphy WJ, Longo DL, Taub DD, Oppenheim JJ Identification of defensin-1, defensin-2, and CAP37/azurocidin asT-cell chemoattractant proteins released from interleukin-8-stimulated neutrophils. J Biol Chem 1996 271 2935. 

Clarke DJ, Campopiano DJ (2006) Structural and functional studies of defensin-inspired peptides. Biochem Soc Trans 34 251-256... 

Kohling, H.L., Bittner, A., Miiller, K.-D., Buer,)., et al (2012) Direct identification of bacteria in urine samples by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry and relevance of defensins as interfering factors. J. Med. Microbiol, 61, 339-344. 

Valore EV, Cans T. Posttranslational processing of defensins ii immature human myebid cells. Blood 1992 79 1538-1544. 

Hill CP, Yee J. Selsted ME, Eisenbe D. Crystal stiuctuie of defensin HNP 3, an amphiphilic dimer Mechanisms of membrane peimeabilitation. Science 1991 251 1481-1485. 

A subset of defensins, the P-defensins, have been isolated from bovine neutrophils (10). A unique consensus sequence distinguishes these defensins from those described above, although both contain the characteristic three disulfide bridges. Tracheal antimicrobial peptide (TAP) isolated from the bovine respiratory tract also contains the triple disulfide motif but is specifically expressed in the lespiratory tract (II). This peptide is active against Cram-negative and -positive bacteria and yeast,... 

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