Document Type : Research Paper

Authors

University Of Baghdad - College of Science

Abstract

The aim of this work is to characterize spectrophotometrically the isolated Alpha fetoprotein from human colorectal tumor homogenates and the molecules of both AFP antibody and the complex of AFP/anti AFP antibody.Gel filtration technique was used to separate 125I-anti AFP antibody bound to human AFP from unbound (free) 125I-anti AFP antibody. The characterization of human-AFP, anti-AFP, and (AFP/Anti-AFP) complex were carried out through the ultraviolet (U.V) spectroscopic studies.Factors affecting the light absorption properties of the molecules under investigation in this work such as pH, solvent polarity (solvent perturbation technique), spectrophotometric pH titration and thermal stability have been studied.The spectrophotometric pH titration for h-AFP, anti AFP, and (AFP/anti-AFP) complex showed that pKa for tyrosine was 9.5, 10.2, and 9.9, while for histidine was 5.7, 6.0, and 5.9 respectively. Spectrophotometric pH titration and several spectral changes were obtained in the presence of different polar and non-polar solvents, like the alteration of max position and intensities of protein spectrum, and the appearance of new chromophores on the surface of protein molecule. These chromophores where embedded in an interior region of the protein in the absence of the solvent.The difference in pH and polarity of the solvents is very important thing to characterize the protein molecules spectrophotometrially because they change the positions and values of molecules λmax in the UV region.

Keywords

Main Subjects

  1. Salvay, A. G., J. Santos, and E. I. Howard. 2007. Electro-optical properties characterizationof fish type III antifreeze protein. J. Biol. Phys. 33:389-397.
  2. Devlin, T.M. “Text Book of Biochemistry with Clinical Correlation” 2nd ed. John Wiley and Sons, Inc, New York; 1986; pp.125, 66.
  3. Svergun, D. I. 1999. Restoring low resolution structure of biological macromolecules from solution scattering using simulated annealing. Biophys. J. 77:2896-2896.
  4. Loskowski, M.; Leach, S.J.; Scheraga, H.A.; J. Am. Chem. Soc.; 1960; 5: 71.
  5. Autin L, Montes M, Miteva M, BO Villoutreix. Computer tools to study intermolecular interactions. Recent Adv. In Structural Bioinformatics. 2007 Chapt.9, p1-51 ISBN: 978-81-308-0208-4 in “Research Signpost”, Trivandrum, India
  6. Scheraga, H.A. “Protein Structure” New York, Academic Press; 1961; Chap.VI, pp. 175-287.
  7. Leach, S.J.; Scheraga, H.A.; J. Biol. Chem.; 1960; 235: 2827-2829.
  8. Frauenfelder H., Fenimore P.W., Chen,G., and McMahon B.H.(2006). Protein folding is slaved to solvent motions. PNAS. 103(42):15469-15472.
  9. Chanse, M. W.; Williams, C. A. “Methods in Immunology and Immuno- Chemistry”. New York: Academic Press.; 1968;  Vol. II, Chap. 10, pp. 163.
  10. Sheinerman F B, Novel L, and Honig B, 2000, Electrostatic aspects of protein – protein interaction.curr. opin.struct.biol.;10:153.
  11. Laskowski, M. J.; Herskovits, T. T.; J. Biol. Chem.; 1960; 235: 56-57.
  12. Mason, P. E.; Brady, J. W. J Phys Chem B 2007, 111, 5669–5679.
  13. Skoog, D. A.; Principles of Instrumental Analysis, 6th ed.; Thompson Brooks/Cole: Belmont, CA, 2006, Chapter 28.
  14. Tedder T F and Hoffmann E M, (1981); Immunoradiometric assay for examination and quantitation of Brucella abortus-specific antibodies reactive with the antigen(s) used in the indirect hemolysis test. J Clin Microbiol. 14(4): 415–426.
  15. Freifrlder, D. “Physical Biochemistry: Physical Application to Biochemistry Molecular Biology”. 2nd. Ed., San Francisco: W. H. Freeman & Company; 1982; Chap. 14, pp. 494-591.
  16. Terentiev AA, Moldogazieva NT. Structural and functional mapping of alpha-fetoprotein. Biochemistry (Mosc). 2006 Feb;71(2):120-32
  17. Mathews, Ch K.; Holde, K. E., and Ahern K G. “Biochemistry”.The Benjamin/ Cummings Publishing Co.; 2000; Chap. 6: pp. 193.
  18. Zizkovsky, V.; Strop, P. Korcakova, J. Havranova, M.; Mikes, F.; Ann. N.Y. Acad. Sc.; 1983; 417: 49-56. 
  19. Leong SS, Middelberg AP. Biotechnol Bioeng. 2007 May 1;97(1):99-117.
  20. Uversky, V.N.; Kirkitadze, M.D.; Narizhneva, N.V.; Potekhin, S.A.; Tomashevski, A.Y.; FEBS letters; 1995; 364: 165-167.
  21. Martin, R.B.; Edsall, J.T.; Wetlaufer, D.B.; Hollingworth, B.R.; J. Biol. Chem.; 1958; 233: 1421-1428.
  22. Herskovits, T.T.; J. Biol. Chem.; 1965; 240: 628-638.
  23. Herskovits, T.T.; Sorensen, M.; Biochemistry; 1968; 7: 2523.
  24. Illarionov B, Lee CY, Bacher A, Fischer M, Eisenreich W. J Org Chem. 2005 Nov 25;70(24):9947-54.
  25. Nagacura, S.; Baba, H.; J. Am. Chem. Soc.; 1953; 74: 5693.
  26. Pimentel, G.C.; J. Am. Chem. Soc.; 1957; 79: 3323.
  27. Brealy, G.J.; Kaska, M.; J. Am. Chem. Soc.; 1955; 77: 4462. 
  28. Chittock R.S., Ward S., Wilkinson A.S., et al, (1999). Hydrogen bonding and protein perturbation in β-lactam acyl – enzyme of Streptococcus pneumonia penicillin-binding protein PBP2x. Biochem. J. 338:153-159.
  29. Silvestien R. M., Bassler G. C., and Marril T. C. "Specrtophotometric identification of organic compounds: , 1981, New Yourk, John Wiley and Sons, p 181.
  30. Michael G.G., "Spectrophotometry and Spectrofluorimetry: A practical Approach", 2000. Oxford University Press, New Yourk, p 121.
  31. Miteva MA, Shosheva A, Sose Al, Makinen M, Atanasov B. Theoretical treatment of spectrophotometric tyrosine titration of two beta-lactamases of class A. Comp Ren Bulg Sci. 2001 54:93-6.
  32. Luis A., Burzio, J. and Herbert Wait, (2001).Reactivity of peptidyl – tyrosin to hydroxylation and cross – linking.