Study of the factors influencing peak asymmetry on chromatography using a molecularly imprinted polymer prepared by the epitope approach

Investigations of the effect of sample load on peak asymmetry during chromatography on molecularly imprinted polymer prepared by the epitope approach showed that the shape of the peaks for the template Tyr-Pro-Leu-Gly-NH2 and for acetyl-L-tyrosine ethyl ester changed considerably until a split was observed. In contrast, the asymmetry of the peaks corresponding to oxytocin, which possesses the same C-terminus tripeptide as the template and interacts with the imprinted polymer, remained essentially unaltered. The circular dichroism (CD) spectra of these peptides showed significant dependence on peptide concentration, and the dependence was nearly the same for all the tested peptides. The addition of acetic acid influenced the CD spectra of YPLG and oxytocin but had no influence on the spectrum of acetyl-L-tyrosine ethyl ester. The shape differences in the chromatographic peaks seem to be associated with a solvation mechanism rather than with solute-solute complexation in solution. However, the observed differences in peak asymmetry cannot be completely explained by the mechanisms that have been postulated previously. Our results suggest the formation of triple complexes between a solute molecule (or molecules), an already adsorbed solute molecule, and an adjacent region of the polymeric stationary phase. These triple complexes may influence the retention of analytes and contribute to peak asymmetry.

[1]  K Mosbach,et al.  Towards artificial antibodies prepared by molecular imprinting. , 1996, Clinical chemistry.

[2]  V. Hruby,et al.  Laser Raman spectroscopy and circular dichroism studies of the peptide hormones mesotocin, vasotocin, lysine vasopressin, and arginine vasopressin. Conformational analysis. , 1979, The Journal of biological chemistry.

[3]  J. Giddings.  Kinetic Origin of Tailing in Chromatography. , 1963 .

[4]  D. Urry,et al.  Proposed conformation of oxytocin in solution. , 1971, Proceedings of the National Academy of Sciences of the United States of America.

[5]  Börje Sellergren,et al.  Noncovalent molecular imprinting: antibody-like molecular recognition in polymeric network materials , 1997 .

[6]  R. Woody,et al.  [4] Circular dichroism , 1995 .

[7]  V. Hruby,et al.  Conformation of oxytocin studied by laser Raman spectroscopy. , 1978, Biochimica et biophysica acta.

[8]  A. Rachkov,et al.  Towards molecularly imprinted polymers selective to peptides and proteins. The epitope approach. , 2001, Biochimica et biophysica acta.

[9]  V. Hruby,et al.  300-MHz nuclear magnetic resonance study of oxytocin aqueous solution: conformational implications. , 1973, Proceedings of the National Academy of Sciences of the United States of America.

[10]  K Mosbach,et al.  Mimics of the binding sites of opioid receptors obtained by molecular imprinting of enkephalin and morphine. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[11]  T. Blundell,et al.  Crystal structure analysis of deamino-oxytocin: conformational flexibility and receptor binding. , 1988, Science.

[12]  M. Flegel,et al.  Circular-dichroic spectra of vasopressin analogues and their cyclic fragments. , 1975, European journal of biochemistry.

[13]  A. Rachkov,et al.  Recognition of oxytocin and oxytocin-related peptides in aqueous media using a molecularly imprinted polymer synthesized by the epitope approach. , 2000, Journal of chromatography. A.

[14]  D. Urry,et al.  Conformational studies on neurohypophyseal hormones: the disulfide bridge of oxytocin. , 1968, Proceedings of the National Academy of Sciences of the United States of America.

[15]  I. Nicholls,et al.  Spectroscopic Evaluation of Molecular Imprinting Polymerization Systems , 1997 .

[16]  K. Mosbach,et al.  Study of the nature of recognition in molecularly imprinted polymers , 1996, Journal of molecular recognition : JMR.

[17]  S. Beychok,et al.  Circular dichroism of oxytocin and several oxytocin analogues. , 1968, The Journal of biological chemistry.

[18]  V. Hruby,et al.  Conformational comparisons of oxytocin agonists, partial agonists, and antagonists using laser Raman and circular dichroism spectroscopy. Examination of 1-penicillamine and diastereoisomeric analogues. , 1982, The Journal of biological chemistry.

[19]  V J Hruby,et al.  Exploration of the conformational space of oxytocin and arginine-vasopressin using the electrostatically driven Monte Carlo and molecular dynamics methods. , 1998, Biopolymers.

[20]  Börje Sellergren,et al.  Origin of peak asymmetry and the effect of temperature on solute retention in enantiomer separations on imprinted chiral stationary phases , 1995 .

[21]  J. Feeney,et al.  Conformational studies of oxytocin and lysine vasopressin in aqueous solution using high resolution NMR spectroscopy. , 1971, Nature: New biology.

[22]  L. Andersson,et al.  Molecular imprinting: developments and applications in the analytical chemistry field. , 2000, Journal of chromatography. B, Biomedical sciences and applications.

[23]  I. Nicholls,et al.  Recognition and enantioselection of drugs and biochemicals using molecularly imprinted polymer technology. , 1995, Trends in biotechnology.

[24]  R. Bhaskaran,et al.  Conformational properties of oxytocin in dimethyl sulfoxide solution: NMR and restrained molecular dynamics studies , 1992, Biopolymers.

[25]  Karsten Haupt,et al.  Herbicide Assay Using an Imprinted Polymer-Based System Analogous to Competitive Fluoroimmunoassays , 1998 .

[26]  V. Remcho,et al.  Peer Reviewed: MIPs as Chromatographic Stationary Phases for Molecular Recognition. , 1999, Analytical chemistry.

[27]  H. Scheraga,et al.  A Raman spectroscopic investigation of the disulfide conformation in oxytocin and lysine vasopressin. , 1977, Biochemistry.

[28]  B. Sellergren.  Polymer- and template-related factors influencing the efficiency in molecularly imprinted solid-phase extractions , 1999 .

[29]  John W. Dolan,et al.  Introduction to modern liquid chromatography , 1974 .

[30]  K. Mosbach,et al.  Study of the nature of recognition in molecularly imprinted polymers , 1996 .

[31]  R. Deslauriers,et al.  CONFORMATIONAL FLEXIBILITY OF THE NEUROHYPOPHYSEAL HORMONES OXYTOCIN AND LYSINE-VASOPRESSIN, A CARBON-13 SPIN-LATTICE RELAXATION STUDY OF BACKBONE AND SIDE CHAINS , 1974 .

[32]  N. Greenfield.  Methods to estimate the conformation of proteins and polypeptides from circular dichroism data. , 1996, Analytical biochemistry.

[33]  C. P. Smith,et al.  Conformational flexibility of the neurohypophyseal hormones oxytocin and lysine-vasopressin. A carbon-13 spin-lattice relaxation study of backbone and side chains. , 1974, Journal of the American Chemical Society.

[34]  Klaus Mosbach,et al.  Highly enantioselective and substrate-selective polymers obtained by molecular imprinting utilizing noncovalent interactions. NMR and chromatographic studies on the nature of recognition , 1988 .

[35]  K. Mosbach,et al.  Molecularly imprinted polymers and their use in biomimetic sensors. , 2000, Chemical reviews.

[36]  M. Kodı́ček,et al.  Chiroptical properties of carba-analogues of oxytocin: Conformational considerations , 1974 .

[37]  G. Wulff.  Molecular Imprinting in Cross‐Linked Materials with the Aid of Molecular Templates— A Way towards Artificial Antibodies , 1995 .

[38]  L. Andersson,et al.  Application of molecular imprinting to the development of aqueous buffer and organic solvent based radioligand binding assays for (s)-propranolol. , 1996, Analytical chemistry.