We propose to analyze key problems in the aggregation process of biological macromolecules. We have assembled an interdisciplinary group to develop experimental and numerical approaches to determine complex structures made of charged units. Biological organisms are always surrounded by a three dimensional environment which they synthesize themselves. From a materials science point of view, this environment can be viewed as an extremely complex microstructure. Molecular biology has experienced an explosive development over the past decades. This fact, combined with the current sophistication in materials characterization and synthetic chemistry, makes this a great period in science to explore the biomolecule-material interface. We propose to address key issues regarding self-assembly of DNA in various ionic media and the interactions between these aggregates and surfaces. We will develop ways to determine the statistics, thermodynamics and structure of DNA based aggregates. We will also design and synthesize molecular structures to be used to determine experimentally the stability of these aggregates near surfaces by using x-ray standing waves and x-ray reflectivity.

National Institute of Health (NIH)
National Institute of General Medical Sciences (NIGMS)
Research Project (R01)
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Biophysical Chemistry Study Section (BBCB)
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Lewis, Catherine D
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Northwestern University at Chicago
Engineering (All Types)
Schools of Engineering
United States
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Cheng, Hao; Zhang, Kai; Libera, Joseph A et al. (2006) Polynucleotide adsorption to negatively charged surfaces in divalent salt solutions. Biophys J 90:1164-74
Solis, F J; Stupp, S I; de la Cruz, M Olvera (2005) Charge induced pattern formation on surfaces: segregation in cylindrical micelles of cationic-anionic peptide-amphiphiles. J Chem Phys 122:54905
Libera, Joseph A; Gurney, Richard W; Schwartz, Craig et al. (2005) Comparative X-ray standing wave analysis of metal-phosphonate multilayer films of dodecane and porphyrin molecular square. J Phys Chem B 109:1441-50
Libera, Joseph A; Cheng, Hao; Olvera de la Cruz, Monica et al. (2005) Direct observation of cations and polynucleotides explains polyion adsorption to like-charged surfaces. J Phys Chem B 109:23001-7
Liu, Xiaogang; Zhang, Yi; Goswami, Dipak K et al. (2005) The controlled evolution of a polymer single crystal. Science 307:1763-6
Velichko, Y S; de la Cruz, M Olvera (2005) Pattern formation on the surface of cationic-anionic cylindrical aggregates. Phys Rev E Stat Nonlin Soft Matter Phys 72:041920
Libera, Joseph A; Gurney, Richard W; Nguyen, SonBinh T et al. (2004) X-ray nanoscale profiling of layer-by-layer assembled metal/organophosphonate films. Langmuir 20:8022-9
Ermoshkin, A V; Kudlay, A N; Olvera de la Cruz, M (2004) Thermoreversible crosslinking of polyelectrolyte chains. J Chem Phys 120:11930-40
Jin, Hua; Kinser, C Reagan; Bertin, Paul A et al. (2004) X-ray studies of self-assembled organic monolayers grown on hydrogen-terminated Si(111). Langmuir 20:6252-8
Kudlay, Alexander; Ermoshkin, Alexander V; de la Cruz, Monica Olvera (2004) Phase diagram of charged dumbbells: a random phase approximation approach. Phys Rev E Stat Nonlin Soft Matter Phys 70:021504

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