In: Biology
Can AMPs that are mainly used for gram-negative bacteria be used on gram-positive as well?
AMP , the Antimicrobial Peptides are the Host defense Peptides (HDP). AMP's have been demonstrated to kill Gram-negative and Gram- positive bacteria enveloped in Viruses,fundi and even Cancerous cells.AMPs can possess multiple activities including anti-gram-positive bacterial, anti-gram-negative bacterial, anti-fungal, anti-viral, anti-parasitic, and anti cancer activities. Their antimicrobial mechanisms are different from traditional antibiotics.So they are capable of being applied to treat various microbes and even drug-resistant ones.
Yes, the AMP's can be used for both Gram-negative and Gram -positive bacteria as well. Antimicrobial peptides (AMPs) have remarkably different structures as well as biological activity profiles, whereupon most of these peptides are supposed to kill bacteria via membrane damage.
The membrane systems of Gram-positive and Gram-negative bacteria and the action mechanisms of AMPs on the cytoplasmic membrane. For Gram negative bacteria, the AMP needs to permeabilize the outer membrane before reach the cytoplasmic membrane, and for Gram positive bacteria, the AMP only needs to diffuse through the peptidoglycan layer via nano-sized pores. After adsorption onto the cytoplasmic membrane, the AMP can induce membrane pores or defragment the membrane.
Before AMPs can interact with the cytoplasmic membrane of Gram-positive bacteria, they have to traverse the cell wall composed of wall- and lipoteichoic acids and peptidoglycan.The intercation of AMP with peptidoglycan will facilitate penetration and interaction with anionic acids may act as either a trap for AMP or ladder for its route to the cytoplasmic membrane. This interaction with cytoplasmic membrane leads to lipid segragation which affects membrane permeability and inhibits cell division.Further precursors of cell wall components are directly targeted by the AMPs.Thereby, the peptides do not inhibit peptidoglycan synthesis via binding to proteins like common antibiotics, but form a complex with the precursor molecule, which can promote pore formation and membrane disruption. Thus, the multifaceted mode of actions will make AMPs superior to antibiotics that act only on one specific target.