Molinets, Zachary B. M. S., Purdue University, August 2014. Investigation Into the Control of Melittin Secondary Structure and Antimicrobial Activity. Major Professor: Jean A. Chmielewski. Antimicrobial resistance has been an exponentially growing problem since the discovery of antibiotics. Antibiotics have been misused for many years and this misuse has grown into a real problem for the medica...

1. Both normal and sarcomatous fibroblasts of the rat utilize many different fragments of the protein molecule for their growth in vitro. Alpha and beta proteoses have approximately equal growth-promoting power. 2. A mixture of peptones, peptides, and amino acids, containing a negligible quantity of proteose, produces a temporary proliferation of normal fibroblasts, and an unlimited multiplicat...

interaction between urokinase-type plasminogen activator (upa) and its receptor (upar) plays an important role in the progression of numerous cancer types including breast cancer by promoting tumor initiating,  proliferation,  invasion  and  metastasis.  hence,  disruption  of  this  interaction  inhibits  their downstream cascades and subsequently tumor growth. for this, we created two series ...

Formation of amyloid oligomers, the most toxic species of amyloids in degenerative diseases, is critically coupled to the interplay with surrounding water. The hydrophobic force driving the oligomerization causes water removal from interfaces, changing the surface-hydration properties. Here, we show that such effects alter the magnetic relaxation response of local water in ways that may enable ...

Synthetic insecticides are very efficient in insect control but can be harmful for the environment and health. They cause disturbances in ecosystem functioning, are toxic for a wide range of non-target organisms, and have a high tendency to accumulate in the environment. Because of this, some alternatives are being sought. A good solution seems to use biologically active peptides like peptide h...

Polymerization of the amyloid beta-peptide (Abeta) has been identified as a major feature of the pathogenesis of Alzheimer's disease (AD). Inhibition of the formation of these toxic polymers of Abeta has thus emerged as an approach to developing therapeutics for AD. Techniques for studying Abeta polymerization include the use of fibril nucleation and extension assays in a variety of formats. De...

Sea anemones produce a myriad of toxic peptides and proteins of which a large group acts on voltage-gated Na+ channels. However, in comparison to other organisms, their venoms and toxins are poorly studied. Most of the known voltage-gated Na+ channel toxins isolated from sea anemone venoms act on neurotoxin receptor site 3 and inhibit the inactivation of these channels. Furthermore, it seems th...

Tau is a microtubule associated protein implicated in the pathogenesis of several neurodegenerative diseases. Because of the channel forming properties of other amyloid peptides, we employed planar lipid bilayers and atomic force microscopy to test tau for its ability to form ion permeable channels. Our results demonstrate that tau can form such channels, but only under acidic conditions. The c...

In the forthcoming era of cancer gene therapy, efforts will be devoted to the development of new efficient and non-toxic gene delivery vectors. In this regard, the use of Fmoc/Boc-protected oligo(ethane amino) acids as building blocks for solid-phase-supported assembly represents a novel promising approach towards fully controlled syntheses of effective gene vectors. Here we report on the synth...

Amyloid cascades that lead to peptide β-sheet fibrils and plaques are central to many important diseases. Recently, intermediate assemblies of these cascades were identified as the toxic agents that interact with cellular machinery. The location and cause of the transformation from a natively unstructured assembly to the β-sheet oligomers found in all fibrils is important in understanding disea...