Abstract
Thermal and stability properties of B17, the 17 % N-terminal domain of apo B, were carried out using differential scanning calorimetry spectroscopy, where the thermal characteristics of the polypeptide were studied and analyzed. The heat capacity data of B17 showed that the protein undergoes two transitions between 50 and 90 °C, with T m’s at 65.9 and 74.8 °C. While the first transition showed immediate reversibility, the second one—with the higher T m—necessitated a longer cooling (several days) period for its reversibility to be observed and both transitions could be seen in the heat capacity profile of B17. Moreover, the van’t Hoff enthalpies determined via calorimetric measurements agreed with the values calculated from the CD analysis reported previously.
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References
Al-Ali H, Khachfe HM (2007) The N-terminal domain of apolipoprotein B-100: structural characterization by homology modeling. BMC Biochem 8:12
Baynes JW, Dominiczak MH (2009) Medical biochemistry, 3rd edn. Mosby Elsevier, London
Chen SH, Yang CY, Chen PF, Setzer D, Tanimura M, Li WH, Gotto AM, Chan L (1986) The complete cDNA and amino acid sequence of human apolipoprotein B-100. J Biol Chem 261(28):12918–12921
Cladaras C, Hadzopoulou-Cladaras M, Nolte RT, Atkinson D, Zannis VI (1986) The complete sequence and structural analysis of human apolipoprotein B-100: relationship between apoB-100 and apoB-48 Forms. EMBO J 5:3495–3506
Freire E, Biltonen R (1978) Estimation of molecular averages and equilibrium fluctuations in lipid bilayer systems from the excess heat capacity function. Biochim Biophys Acta 514(1):54–68
Herscovitz H, Derksen A, Walsh MT, McKnight CJ, Gantz DL, Hadzopoulou-Cladaras M, Zannis V, Curry C, Small DM (2001) The N-terminal 17% of apoB binds tightly and irreversibly to emulsions modeling nascent very low density lipoproteins. J Lipid Res 42(1):51–59
Jané R, Laguna P, Thakor NV, Caminal P (1992) Adaptive baseline wonder removal in the ECG comparative analysis with cubic spline technique. Proceedings of the IEEE computers in cardiology conference
Khachfe HM (2002) Spectroscopic and calorimetric studies of the 17% N-terminal domain of apolipoprotein B-100. Ph.D. dissertation, Department of Physiology and Biophysics, Boston University
Khachfe HM, Atkinson D (2011) Cloning, expression, purification, and quantification of the 17% N-terminal domain of apolipoprotein b-100. J Cel Mol Biol (JCMB) 9(2):53–60
Khachfe HM, Atkinson D (2012) Conformation and stability properties of B17: I. Analytical investigations using circular dichroism. Eur Biophs J 41(8):639–646. doi:10.1007/s00249-012-0836-2
Knott TJ, Pease RJ, Powell LM, Wallis SC, Rall SC Jr, Innerarity TL, Blackhart B, Taylor WH, Marcel Y, Milne R, Johnson D, Fuller M, Luisi AJ, McCarthy BJ, Mahley RW, Levy-Wilson B, Scott J (1986) Complete protein sequence and identification of structural domains of human apolipoprotein B. Nature 323(6090):734–738
Law SW, Grant SM, Higuchi K, Hospattankar A, Lackner K, Lee N, Brewer HB Jr (1986) Human liver apolipoprotein B-100 cDNA: complete nucleic acid and derived amino acid sequence. Proc Natl Acad Sci USA 83:8142–8146
Murphy KP, Privalov PL, Gill SJ (1990) Common features of protein unfolding and dissolution of hydrophobic compounds. Science 247:559–561
Nolte RT (1994) Structural analysis of the human apolipoproteins: an integrated approach utilizing physical and computational methods. Ph.D. dissertation, Department of Biophysics, Boston University
Poulos GW (2001) The three dimensional structure of low density lipoprotein via cryoelectron microscopy. Ph.D. dissertation, Department of Biophysics, Boston University
Privalov PL (1979) Stability of proteins: small globular proteins. Adv Protein Chem 33:167–241
Privalov PL (1982) Stability of proteins. Proteins which do not present a single cooperative system. Adv Protein Chem 35:1–104
Privalov PL, Makhatadze GI (1990) Heat capacity of proteins. II-Partial molar heat capacity of the unfolded polypeptide chain of proteins: protein unfolding effects. J Mol Biol 213(2):385–391
Privalov PL, Potekhin SA (1986) Scanning microcalorimetry in studying temperature-induced changes in proteins. Methods Enzymol 131:4–51
Sturtevant JM (1974) Some applications of calorimetry in biochemistry and biology. Ann Rev Biophys Bioeng 3:35–51
Turunen O, Etuaho K, Fenel F, Vehmaanpera J, Wu X, Rouvinen J, Leisola M (2001) A combination of weakly stabilizing mutations with a disulfide bridge in the alpha-helix region of Trichoderma reesei endo-1,4-beta-xylanase II increases the thermal stability through synergism. J Biotechnol 88(1):37–46
Walsh MT, Atkinson D (1990) Calorimetric and spectroscopic investigation of the unfolding of human apolipoprotein B. J Lipid Res 31:1051–1062
Yang C-y, Yang T, Pownall HJ, Gotto AM Jr (1986) The primary structure of apolipoprotein A-I from rabbit high-density lipoprotein. Eur J Biochem 160:427–431
Acknowledgments
Special thanks should go to Dr. D. Small and the late Dr. M. Walsh for their insightful discussions. This project was partially supported by an award from the National Institutes of Health (NIH).
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Khachfe, H.M., Atkinson, D. Conformation and stability properties of B17: II. Analytical investigations using differential scanning calorimetry. Eur Biophys J 42, 309–314 (2013). https://doi.org/10.1007/s00249-012-0876-7
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DOI: https://doi.org/10.1007/s00249-012-0876-7