Purification and characterization of a novel antimicrobial peptide (QAK) from the hemolymph of Antheraea mylitta.
Biochem Biophys Res Commun
; 527(2): 411-417, 2020 06 25.
Article
en En
| MEDLINE
| ID: mdl-32334835
ABSTRACT
Antheraea mylitta, a tropical non-mulberry silkworm, is cultivated for tasar silk production in India. Several defense molecules including few antimicrobial peptides (AMPs) and proteins have been identified from this insect. Here, we have isolated and purified an antimicrobial tri-peptide by sequential chromatographic separation procedures. The amino acid sequence of the peptide was determined as NH2-Gln-Ala-Lys-COOH (QAK) using MALDI MS/MS fragmentation analysis. Further, the peptide was synthesized in vitro following solid phase chemistry of peptide synthesis and acetylated by acetic anhydride reaction. Antimicrobial activities of non-acetylated and acetylated QAK were tested against both Escherichia coli and Staphylococcus aureus bacteria. Acetylated peptide inhibited bacterial growth more effectively and its minimum inhibitory concentration (MICs) was found lower than non-acetylated peptide. SEM studies revealed more membrane damage and release of intracellular materials like ß-galactosidase enzyme from acetylated peptide treated bacteria in comparison to non-acetylated QAK. At MIC, acetylated peptide did not show any significant hemolytic activity against rabbit erythrocytes. The results suggest that acetylated-QAK is a promising new antimicrobial peptide and can be used for therapeutic purpose.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Hemolinfa
/
Proteínas de Insectos
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Proteínas Citotóxicas Formadoras de Poros
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Antibacterianos
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Mariposas Nocturnas
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Biochem Biophys Res Commun
Año:
2020
Tipo del documento:
Article
País de afiliación:
India