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Solution structure of moricin, an antibacterial peptide, isolated from the silkworm Bombyx mori
Author(s) -
Hemmi Hikaru,
Ishibashi Jun,
Hara Seiichi,
Yamakawa Minoru
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02637-6
Subject(s) - bombyx mori , peptide , helix (gastropod) , alpha helix , peptide sequence , amphiphile , chemistry , amino acid , stereochemistry , antibacterial activity , antibacterial peptide , circular dichroism , crystallography , biochemistry , bacteria , biology , organic chemistry , copolymer , polymer , ecology , genetics , snail , gene
A novel antibacterial peptide, moricin, isolated from the silkworm Bombyx mori , consists of 42 amino acids. It is highly basic and the amino acid sequence has no significant similarity to those of other antibacterial peptides. The 20 structures of moricin in methanol have been determined from two‐dimensional 1 H‐nuclear magnetic resonance spectroscopic data. The solution structure reveals an unique structure comprising of a long α‐helix containing eight turns along nearly the full length of the peptide except for four N‐terminal residues and six C‐terminal residues. The electrostatic surface map shows that the N‐terminal segment of the α‐helix, residues 5–22, is an amphipathic α‐helix with a clear separation of hydrophobic and hydrophilic faces, and that the C‐terminal segment of the α‐helix, residues 23–36, is a hydrophobic α‐helix except for the negatively charged surface at the position of Asp30. The results suggest that the amphipathic N‐terminal segment of the α‐helix is mainly responsible for the increase in permeability of the membrane to kill the bacteria.