Effect of GNP functionalisation and multiple N-methylation of β-amyloid residue (32-37) on Gram-positive bacterium.

In the previous report, the authors showed the gold nanoparticle (GNP) functionalised multiple N-methylated fragments of the residue (32-37) of beta (β)-amyloid protein (1-42), CGGIGLMVG and CGGGGGIGLMVG toward disruption of β-amyloid (1-42), the predominant component of senile plaques. Herein the in vitro antimicrobial activities of both normal and multiple N-methylated sequences of CGGIGLMVG and CGGGGGIGLMVG were screened and it was found that all the eight sequences including four (non-functionalised with GNP) to possess activity against both Gram-positive [Staphylococcus aureus (ATCC 43300) and Enterococcus faecalis (ATCC 5129)] and Gram-negative [Escherichia coli (ATCC 35218), Pseudomonas aeruginosa (ATCC 27853) and Klebsiella pneumoniae (ATCC 700603)] bacteria. Among them, N-methylated sequences CGGIGLMVG and CGGGGGIGLMVG shown remarkable activity against Gram-positive bacteria.