Antimicrobial peptides linear

Blazyk J, Wiegand R, Klein J, Hammer J, Epand RM, Epand RF, Maloy WL, Kari UP (2001) A novel linear amphipathic beta-sheet cationic antimicrobial peptide with enhanced selectivity for bacterial lipids. J Biol Chem 276 27899-27906... 

The amphipathic a-helical class of host defense peptides is the most abundant and most well-characterized class. Upon interaction with the hydrophobic membrane environment, the largely unstructured peptide adopts an amphipathic ct-helical conformation with one helical face containing the majority of the hydrophobic residues, the opposite containing a large proportion of the polar residues. These peptides are often short (<40 amino acids), devoid of cysteine residues, and found to be unstructured or linear in nonhydrophobic environments. Peptides found within this class include the antimicrobial peptide alamethicin, bee venom melittin, the magainins, and the human cathelicidin LL-37. ... 

Short Linear Cationic Antimicrobial Peptides Screening, Optimizing, and Prediction... 

Qren, Z. and Shai, Y. (1998) Mode of action of linear amphipathic a-hehcal antimicrobial peptides. Biopolymers, 47, 451 —463. 

Antimicrobial peptides have been investigated by solid-state NMR spectroscopy when they are reconstituted into oriented phospholipid bilayers. Solid-state NMR spectroscopy have shown that magainins exhibit potent antimicrobial activities when their cationic amphipathic helix is oriented parallel to the bilayer surface, a configuration found in later years for many other linear cationic amphipathic peptides. This was different for other classes of peptides. In addition the effect on the membrane was also examined by P and NMR. 

Bromotyrosine-derived metabolites are often encountered in marine sponges of the families Aplysinidae and Pseudocer-atidae, in particular Pseudoceratina (= Psammaplysilla) purpurea. They show a variety of biological activities, which include antimicrobial, enzyme inhibitory, and antifouling activities. Psammaplysin A (47) is antimicrobial, cytotoxic, and antifouling, whereas psammaplin A (48) is an inhibitor of histone deacetylase (2). The marine sponge lanthella basta synthesizes at least 25 bastadins that are linear or cyclic peptides composed of four bromotyrosine residues [bastadin 5 (49)] and show antimicrobial, cytotoxic, and enzyme inhibitory activities as well as interaction with Ca + channels (21). 

A totally retro-inverso peptide is an isomer of a linear peptide in which the direction of the amino acid sequence is reversed and the chirality at the C carbon of the residues is inverted. This modification has been widely applied [83]. Antigenicity and immunogenic-ity have been demonstrated by preparation of retro-inverso isomers of natural antigenic peptides [84], Retro-inverso forms derived from mellitin and cercropin A maintain antimicrobial activity [85]. A cyclic retro-enantiomeric D amino acid peptide has been designed and shown to be active as synthetic inhibitor of the interaction between immunoglobulin E (IgE) and its high-affinity receptor FceRl [86]. 

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