Purdue School of Science Research Award, 1993.
The interaction of DNA with nucleic acid binding
proteins in transcription and storage is one example of in vivo
association between proteins and polyelectrolytes. The biological
anionic polysaccharides heparin, hyaluronic acid and chondroitin
sulfate also bind proteins, but less is known about binding mechanism
or energetics. These questions, as well as the use of synthetic
polyelectrolytes to fractionate and immobilize proteins, motivates
our work in the area of protein-polyelectrolyte complexes. We use
light scattering, electrophoresis, fluorescence spectroscopy and
capillary electrophoresis to characterize the structure of soluble
protein-polyelectrolyte complexes, and we couple these results to
computer modeling.
Similar techniques are being applied to other systems in which
polyelectrolytes interact with small colloids: surfactant micelles,
and dendrimers. The results are relevant to technological problems
in the stabilization and flocculation of industrial dispersions
and pharmaceutical/cosmetic formulations.
We are examining separations of proteins and smaller molecules
by size-exclusion chromatography, ion-exchange chromatography, and
by capillary electrophoresis. The focus of this work is on the role
of solute geometry and electrostatic interactions in determining
retention.
"The Roles of Electrostatic Interaction and Polymer Structure
in the "Compositional Heterogeneity in Nonionic/Anionic Mixed
Micelles Observed by Frontal Analysis Continuous Capillary Electrophoresis"
Langmuir18,
4605-4609 (2002) (with B. Zhang and G.F. Kirton).
"Identification by Integrated Computer Modeling and Light
Scattering Studies of an Electrostatic Serum Albumin-Hyaluronic
Acid Binding Site", Biomacromolecules 2 422-429 (2001). (with
K. Grymonpré, B. Staggemeir, and
K.W. Mattison).
"Adsorptive Partitioning of an Organic Compound onto Polyelectrolyte-Immobilized
Micelles on Porous Glass and Sand" Environmental Science
and Technology, 35 2608-2611 (2001) (with Y. Wang, J. Banziger,
G.Filipelli and N. Nuraje),
"Binding of Bovine Serum Albumin to Heparin Determined by
Turbidimetric Titration and Frontal Analysis Continuous Capillary
Electrophoresis", Analytical Biochemistry, 295, 158-167 (2001)
(with T. Hattori, K. Kimura and
E. Seyrek).
"Interaction of DNA with Cationic Micelles: Effects of Micelle
Surface Charge Density, Micelle Shape and Ionic Strength on Complexation
and DNA Collapse", Langmuir 17 1670-1673 (2001) with Y. Wang
and H. Zhang).
"Counterion Binding on Charged Spheres: Effect of pH and
Ionic Strength on the Mobility of Carboxyl-terminated Dendrimers,
J. Phys. Chem B 104, 898-904 (2000) (with Q.R. Huang, C.N. Moorefield
and G.R. Newkome).
Binding of b-Lactoglobulin to Anionic Polyelectrolytes: Measurement
of Binding Constants by FACCE", Langmuir16 9738-9743 (2000)
(with T. Hattori and R. Hallberg).
"Small Angle Neutron Scattering of Charged Carboxyl-terminated
Dendrimers in Solution", submitted, J. Phys. Chem. (with
W. R. Huang, J. Lal, C.N. Moorefield and G.R. Newkome).
"Coacervation of Bovine Serum Albumin with Cationic Polyelectrolytes",
submitted, BioMacromolecules, (with K. Kaibara, T. Okazaki, and
H.P. Bohidar).
“Determination of the Compositional Distribution of Copolymers
by Frontal Analysis Continuous Capillary Electrophoresis”,
Analytical Chemistry, 72(1), 255-258 (2000) (with B. Staggemeier,
Q. R. Huang, Y. Morishima and T. Sato).
“Counterion Binding on Charged Spheres: Effect of pH and
Ionic Strength on the Mobility of Carboxyl-Terminated Dendrimers”,
The Journal of Physical Chemistry B, 104(5), 898-904 (2000)(with
Q. R. Huang, C. N. Moorefield and G. R. Newkome).
"Light scattering, circular dichroism and Ligand Binding
Studies of Hemoglobin-Polyelectrolyte Complexes", Biopolymers,
50, 153 (1999) (with J. Xia, B. Muhoberac*, E. Kokufuta, and H.
Havel).
"Capillary Modification by Noncovalent Polycation Adsorption:
Effects of Polymer Molecular Weight and Adsorption Ionic Strength"
Anal. Chem., 71, 3463-8 (1999) (with Y. Wang)
"Effects of Salt on Polyelectrolyte-Micelle Coacervation",
Macromolecules; 32, 7128-7134 (1999) (with Y. Wang, K. Kimura,
Q.R. Huang and W. Jaeger)
“Formation of an intrapolymer complex from
human serum albumin and poly(ethyleneglycol)”, Langmuir,
15 (4), 940-947 (1999) (with S. Azegami, a. Tsuboi, T. Izumi,
M. Hirata, B. Wang and E. Kokufuta).
"Complex Formation by Electrostatic Interaction
between Carboxyl-terminated Dendrimer and Oppositely Charged Polyelectrolyte",
submitted, Langmuir (N. Miura, P. L. Dubin, C.M. Moorefield and
G. Newkome).
"Binding of Proteins to Copolymers of Varying
Hydrophobicity",Biopolymers, 49, 185-193, (J. Gao and P.
L. Dubin).
"Interaction of a Polycation with Small Oppositely
Charged Dendrimers", J. Phys. Chem., J. Phys. Chem., 103,
2347-2354 (1999) (H. Zhang, J. Ray, P. L. Dubin, G.S. Manning,
G.R. Newkome and C.S. Moorefield).
"Effect of pH on the Binding of B-lactoglobulin
to Sodium Polystyrene Sulfonate", J. Phys. Chem.,
102 8629-8633 (1998) (with R. Hallberg and P. L. Dubin).
"Protein Binding on Polyelectrolyte-treated
Glass: Effect of Microscopic Structure of Adsorbed Polyelectrolyte",
J. Chromatogr., 808 61-70 (1998) (Y. Wang and P. L. Dubin).
"Binding of Polycarboxylic Acids to Cationic
Mixed Micelles: Effects of Polymer Counterion Binding and Polyion
Charge Distribution", J. Colloid Interface Sci., 205, 257-264
(1998) (K. Yoshida, S. Sokhakian and P. L. Dubin).
"Permeation of Small Molecules in Aqueous Size-Exclusion
Chromatography vis-a-vis Models for Separation", Analytical
Chemistry 70, 1576-1580 (1998) (H. Dai P. L. Dubin and T. Andersson).
"Fluorescence Quenching Studies of the Interaction
of a Pyrene-labeled Polyelectrolyte with Quencher-Carrying Oppositely
Charged Micelles", Langmuir, 13, 6941-6 (1997) (with M. Mizusaki,
Y. Morishima, P. L. Dubin and K. Yoshida).
"Dissociation of Carboxyl-terminated Cascade
Polymers: Comparison with Theory", J. Phys. Chem., 101, 3494-3497
(1997), ( H. Zhang, P. L. Dubin, J.I. Kaplan, C.N. Moorefield
and G.R. Newkome).
"Measurement of the Binding of Proteins to
Polyelectrolytes by Frontal Analysis Continuous Capillary Electrophoresis,
Anal. Chem. 69, 2945-2951 (1997)(Y. Gao, P. L. Dubin, B. B. Muhobenac).