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Reactivity of Aziridine Aldehyde Dimers and their Utility in the Synthesis of PeptidomimeticsAssem, Naila Magdy 06 December 2012 (has links)
Amino aldehydes are important building blocks in organic synthesis. However, due to the innate propensity for condensation to occur upon combination of aldehydes and amines, uprotected amino aldehydes are unstable. One exception to this is the existence of dimeric aziridine aldehydes. We have shown that the enhanced stability observed with these unprotected aziridine aldehydes is due to their dimeric nature. In addition, we have shown that reversible dimer dissociation plays a key role in the kinetics and stereoselectivity of subsequent reactions.
Reductive amination with the unprotected amino aldehyde dimers occurs without double addition or epimerization. The resulting aziridine conjugates were used towards a convergent synthesis of aminomethylene peptidomimetics, by aziridine ring opening with C-terminal peptide thioacids. We have shown that we can also utilize the aziridine aldehydes towards the assembly of branched peptides.
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The synthesis and properties of radiolabelled melittin derivativesDean, Kevin Raymond January 1990 (has links)
No description available.
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Synthesis of liquid crystalline oligopeptides and discotic molecules designed for additional structure formationCarswell, Robert John January 1998 (has links)
No description available.
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Physical Model for Cell Selectivity of Antimicrobial PeptidesBagheri, Azadeh 14 June 2013 (has links)
Antimicrobial peptides (AMPs) are relatively-short chain molecules that living organisms
use to defend themselves against a wide range of invading microorganisms such as
bacteria and viruses. They selectively bind to and kill microbes over host cells by permeabilizing
cell membranes or by inhibiting the biological functions of intra-cellular components.
Despite its significance in determining their cell selectivity, however, the cell-concentration
dependence of AMP's membrane-perturbing activity has not been criticality examined.
In this thesis, we present a physical model for cell selectivity of AMPs, especially its
cell-concentration dependence. To this end, we use a coarse-grained model that captures
essential molecular details such as lipid composition (e.g., fraction of anionic lipids) and
peptide amphiphilicity and charge. In particular, we calculate the surface coverage of peptides
in the membrane-perturbing mode as a function of peptide and cell densities: those
that bind to the interface between lipid headgroups and tails. This allows us to extract
the minimum inhibitory concentration (MIC) and the minimum hemolytic concentration
(MHC) of the peptides. Our results show that both MIC and MHC increase as the cell density
increases so that the peptide selectivity (given by MHC/MIC) decreases with increasing
cell density. Our results will help resolve conflicting interpretations of peptide-selectivity
experiments.
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Design, synthesis and testing of calpain inhibitors for the treatment of cataractChen, Hongyuan January 2007 (has links)
This thesis reports the development of potent and selective inhibitors of m-calpain for the treatment of cataract. SJA6017 has been proven to prevent lens opacity in rat and has been our lead compound. A series of Val-Leu peptidyl aldehyde inhibitors (33a-e, 33g, 33i and 35) have been designed, synthesized, and tested for therapeutic potential as cataract inhibitors. Chapter 1 is an introduction to calpain and the diseases associated with it's over activation. A review of the literature on calpain inhibition is given. Structure activity relationship (SAR) theory is presented. The techniques that have been applied in our research group to drug design include molecular modeling, synthesis, assay and animal studies which are all briefly discussed. The importance of a -strand conformation for an inhibitor to bind to calpain is discussed. Chapter 2 describes the synthesis of m-calpain inhibitors. This comprises the preparation of the Val-Leu dipeptide core 29, Val-Leu dipeptidyl alcohols 31a-g and 31i, and the synthesis of dipeptidyl aldehydes 33a-e, 33g, 33i and 35. The choice of coupling regents and conditions in the coupling reactions is investigated. Sulfur trioxide pyridine oxidation for the conversion of Val-Leu dipeptidyl alcohols to aldehydes is discussed. The molecular modeling and biological assay results are presented.
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Granulocyte activation by danger signals and blocking of receptor responses /Stenfeldt, Anna-Lena, January 2007 (has links)
Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 4 uppsatser.
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Models for the calculation of peptide vibrational spectraGorbunov, Roman D. Unknown Date (has links)
University, Diss., 2007--Frankfurt (Main). / Zsfassung in dt. Sprache.
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Analysis of NMR chemical shifts in peptide and protein structure determination guide for using a collection of chemical shift data for statistical analysis and its application in protein structure identificationWang, Liya January 1900 (has links)
Zugl.: Madison, Univ. of Wisconsin, Diss., 2006
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Role of calcitonin gene-related peptide in nociception : interactions with substance P and opioids /Yu, Long-Chuan, January 1900 (has links)
Diss. (sammanfattning) Stockholm : Karol. inst. / Härtill 5 uppsatser.
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Differentielle Analyse des Peptidspektrums von Synovia und Blutplasma bei Gonarthrose /Buss, Astrid Johanne. January 2007 (has links)
Zugl.: Hannover, Med. Hochsch., Diss., 2007.
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