Cecropins are antimicrobial peptides. [1 ] They were first isolated from the hemolymph of [2 ] , from whence the term cecropin was derived. Cecropins lyse bacterial cell membranes; they also inhibit proline uptake and cause leaky membranes. Hyalophora cecropia
[3 ] [4 ] constitute a main part of the [5 ] cell-free immunity of insects. Cecropins are small proteins of about 31 - 37 amino acid residues active against both Gram-positive and Gram-negative bacteria. Cecropins isolated from insects other than (Cecropia moth) have been given various names; Hyalophora cecropia bactericidin, lepidopteran, sarcotoxin, etc. All of these peptides are structurally related. Cecropin P1, an intestinal antibacterial peptide from (Pig), also belongs to this family. Cecropin family also consists Sus scrofa Cecropin A and Cecropin B.
Cecropin is an anticancer polypeptide(L). Structure consists of mainly alpha helixes, determined by solution NMR. Protein molecular weight = 4203.4g/mol.
At low peptide to lipid ratios [6 ] ion channels are formed, at high peptide to lipid ratios pores are formed. [7 ]
References [ edit ]
^ Cecropins at the US National Library of Medicine Medical Subject Headings (MeSH)
^ Lauwers A, Twyffels L, Soin R, Wauquier C, Kruys V, Gueydan C (January 2009), "Post-transcriptional regulation of genes encoding anti-microbial peptides in Drosophila", J. Biol. Chem. 284 (13): 8973–83, doi: 10.1074/jbc.M806778200, PMC 2659254, PMID 19176529.
^ Boman HG, Hultmark D (1987), "Cell-free immunity in insects", Annu. Rev. Microbiol. 41: 103–126, doi: 10.1146/annurev.mi.41.100187.000535, PMID 3318666.
^ Boman HG (1991), "Antibacterial peptides: key components needed in immunity", Cell 65 (2): 205–207, doi: 10.1016/0092-8674(91)90154-Q, PMID 2015623.
^ Boman HG, Faye I, Lee JY, Gudmundsson GH, Lidholm DA (1991), "Cell-free immunity in Cecropia. A model system for antibacterial proteins", Eur. J. Biochem. 201 (1): 23–31, doi: 10.1111/j.1432-1033.1991.tb16252.x, PMID 1915368.
^ Protein Data Bank (1930), Solution structure of CB1a, a novel anticancer peptide derived from natural antimicrobial peptide cecropin B [< http://www.rcsb.org/pdb/explore/explore.do?structureId=2IGR> <Protein Data Bank>]
^ Loraine Susan Silvestro, "Function and structure of cecropin A" (January 1, 2000). Dissertations available from ProQuest. Paper AAI9965567. http://repository.upenn.edu/dissertations/AAI9965567