Margaret A Schmitt

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We have previously shown that two synthetic antimicrobial peptides with alternating alpha- and beta-amino acid residues, designated simply as alpha/beta-peptide I and alpha/beta-peptide II, had toxicity toward bacteria and affected the morphology of bacterial membranes in a manner that correlated with their effects on liposomes with lipid composition(More)
We have studied how membrane interactions of two synthetic cationic antimicrobial peptides with alternating alpha- and beta-amino acid residues ("alpha/beta-peptides") impact toxicity to different prokaryotes. Electron microscopic examination of thin sections of Escherichia coli and of Bacillus subtilis exposed to these two alpha/beta-peptides reveals(More)
Molecules that bind to specific surface sites on proteins are of great interest from both fundamental and practical perspectives. We are exploring a ligand development strategy that is based on oligomers with discrete folding propensities ("foldamers"); we target a specific cleft on the cancer-associated protein Bcl-xL because this system is well(More)
Foldamers, oligomers with strong folding propensities, are subjects of growing interest because such compounds offer unique scaffolds for the development of molecular function. We report two new foldamer classes, oligopeptides with regular 1:2 or 2:1 patterns of alpha- and beta-amino acid residues. Two distinct helical conformations are detected via 2D NMR(More)
Host-defense peptides inhibit bacterial growth but manifest relatively little toxicity toward eukaryotic cells. Many host-defense peptides adopt alpha-helical conformations in which cationic side chains and lipophilic side chains are segregated to distinct regions of the molecular surface ("globally amphiphilic helices"). Several efforts have been made to(More)
We describe our first effort to design antimicrobial alpha/beta-peptides based upon their helical folding behavior. alpha/beta-Peptide 3 (above), designed as a scrambled negative control, exhibited the most favorable activity profile, combining high antimicrobial activity with low hemolytic activity. This finding suggests that design principles focused(More)
Design of functional foldamers requires knowledge of the conformational propensities of constituent residues. Here, we explore the effects of variations in both alpha-amino acid and beta-amino acid substitution on alpha/beta-peptide helicity. We also report the first X-ray crystal structure of a helical alpha/beta-peptide. We conclude that a certain amount(More)
Reducing the delivery of phosphorus (P) from land-applied manure to surface water is a priority in many watersheds. Manure application rate can be controlled to manage the risk of water quality degradation. The objective of this study was to evaluate how application rate of liquid swine manure affects the transport of sediment and P in runoff. Liquid swine(More)
Understanding the interactions that drive the fidelity of the genetic code and the limits to which modifications can be made without breaking the translational system has practical implications for understanding the molecular mechanisms of evolution as well as expanding the set of encodable amino acids, particularly those with chemistries not provided by(More)