Submitted to: Biophysical Society Annual Conference
Publication Type: Abstract Only
Publication Acceptance Date: 2/15/2025
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: The pathogen Fusarium graminearum is the causative agent of diseases like head blight in wheat and ear rot in corn, which can result in millions of dollars of revenue loss for the agricultural industry. Current methods of disease treatment rely on fungicides in conjunction with crop management strategies to minimize plant damage. However, overuse of existing fungicides can lead to potential resistance in the fungus and a deleterious impact on the environment. Thus, developing alternative treatments to these methods is important. One such approach is the use of a small 13-amino acid long cationic peptide (FKCKKVVISLRRY), called JH8944, previously found effective against several agricultural pathogens, including F. graminearum. Biophysical methods were utilized to characterize the interaction of this short peptide against liposomes to better understand how it interacts with pathogens. Content leakage experiments showed that JH8944 bound with liposomes composed of phosphatidyl glycerol (DOPG), a negatively charged lipid, caused leakage of the liposomes, likely through membrane disruption. Nano isothermal titration calorimetry experiments demonstrated that the interaction between JH8944 and DOPG liposomes is exothermic in nature, revealing that electrostatic interactions and not hydrophobic interactions drive the binding. Quartz crystal microbalance with dissipation monitoring showed that binding to a negatively charged surface resulted in low dissipation, indicating rigid binding. This suggests that the peptide does not form any extended structure upon accumulation. These findings provide a better understanding of the underlying mechanism for membrane disruption and indicate how AMP JH8944 may be useful in combating fungal issues in crops.