Cecropin
Encyclopedia
Cecropins are antimicrobial peptide
s. They were first isolated from the hemolymph of Hyalophora cecropia
, from whence the term cecropin was derived. Cecropins lyse bacterial cell membranes; they also inhibit proline uptake and cause leaky membranes.
Cecropins constitute a main part of the cell-free immunity of insects. Cecropins are small proteins of about 35 amino acid residues active against both Gram-positive and Gram-negative bacteria. Cecropins isolated from insects other than Hyalophora cecropia
(Cecropia moth) have been given various names; bactericidin, lepidopteran, sarcotoxin, etc. All of these peptides are structurally related. Cecropin P1, an intestinal antibacterial peptide from Sus scrofa (Pig), also belongs to this family.
Cecropin is an anticancer polypeptide(L). Structure consists of mainly alpha helixes, determined by solution NMR. Protein molecular weight = 4203.4g/mol . Sequence and Hydropathy data available at the Protein Data Bank . In vesicles, cecropins are concentration dependent. At low peptide to lipid ratios ion channels are formed, at high peptide to lip ratios pores are formed. IR Spectroscopy was used to determine cecropin's action near cell membranes. Results indicate that cecropins fold while superficially attached to the cell membrane . Cecropins can interact inside the bi-layer, however, this does not directly affect folding.
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s. They were first isolated from the hemolymph of Hyalophora cecropia
Hyalophora cecropia
The Cecropia Moth is North America's largest native moth. It is a member of the Saturniidae family, or giant silk moths. Females with a wingspan of 160 mm or more have been documented. It is found as far west as the Rocky Mountains and north into the maritime provinces of Canada...
, from whence the term cecropin was derived. Cecropins lyse bacterial cell membranes; they also inhibit proline uptake and cause leaky membranes.
Cecropins constitute a main part of the cell-free immunity of insects. Cecropins are small proteins of about 35 amino acid residues active against both Gram-positive and Gram-negative bacteria. Cecropins isolated from insects other than Hyalophora cecropia
Hyalophora cecropia
The Cecropia Moth is North America's largest native moth. It is a member of the Saturniidae family, or giant silk moths. Females with a wingspan of 160 mm or more have been documented. It is found as far west as the Rocky Mountains and north into the maritime provinces of Canada...
(Cecropia moth) have been given various names; bactericidin, lepidopteran, sarcotoxin, etc. All of these peptides are structurally related. Cecropin P1, an intestinal antibacterial peptide from Sus scrofa (Pig), also belongs to this family.
Cecropin is an anticancer polypeptide(L). Structure consists of mainly alpha helixes, determined by solution NMR. Protein molecular weight = 4203.4g/mol . Sequence and Hydropathy data available at the Protein Data Bank . In vesicles, cecropins are concentration dependent. At low peptide to lipid ratios ion channels are formed, at high peptide to lip ratios pores are formed. IR Spectroscopy was used to determine cecropin's action near cell membranes. Results indicate that cecropins fold while superficially attached to the cell membrane . Cecropins can interact inside the bi-layer, however, this does not directly affect folding.