OJBIPHY  Vol.4 No.2 , April 2014
Accuracy of Protein Size Estimates Based on Light Scattering Measurements
Abstract: There are two types of light scattering measurements: static light scattering (SLS) and dynamic light scattering (DLS). The SLS method is used to estimate the molecular weight (MW) of particles by measuring the time-averaged intensity of light scattered by the particles, whereas the DLS method is used to estimate the diffusion coefficient of particles by observing the time-correlation of scattered light intensity. These techniques have recently been applied to the investigation of the aggregation, denaturation and folding, and complex formation of proteins in solution. However, the accuracy of protein size measurement by light scattering is poorly understood. In the present study, we carried out the size measurements of five globular proteins by SLS and DLS at a detection angle of 90。 and compared these data to measurements made by size exclusion chromatography (SEC). The difference (%) between the MW estimated from each method and the MW calculated from the amino acid sequence (namely the calibration residual error) was regarded as an index of measurement accuracy. The averaged calibration residual errors were 5.2 and 4.7 for SEC and SLS measurements, respectively. For the DLS measurements, the extrapolation of the apparent hydrodynamic radii to a protein concentration of zero may effectively eliminate the interparticle and hydrodynamic interactions and significantly reduced the averaged calibration residual error to 4.8%. Our results suggested that the size of globular proteins can be estimated using light scattering measurements with an accuracy equivalent to that of SEC.
Cite this paper: Takeuchi, K. , Nakatani, Y. and Hisatomi, O. (2014) Accuracy of Protein Size Estimates Based on Light Scattering Measurements. Open Journal of Biophysics, 4, 83-91. doi: 10.4236/ojbiphy.2014.42009.

[1]   Laue, T.M. and Rhodes, D.G. (1990) Determination of Size, Molecular Weight, and Presence of Subunits. Methods in Enzymology, 182, 566-587.

[2]   Murphy, R.M. (1997) Static and Dynamic Light Scattering of Biological Macromolecules: What Can We Learn? Current Opinion in Biotechnology, 8, 25-30.

[3]   Bohidar, H.B. (1998) Light Scattering and Viscosity Study of Heat Aggregation of Insulin. Biopolymers, 45, 1-8.<1::AID-BIP1>3.0.CO;2-X

[4]   Sasahara, K., Yagi, H., Sakai, M., Naiki, H. and Goto, Y. (2008) Amyloid Nucleation Triggered by Agitation of B2-Microglobulin under Acidic and Neutral pH Conditions. Biochemistry, 47, 2650-2660.

[5]   Liu, W., Cellmer, T., Keerl, D., Prausnitz, J.M. and Blanch, H.W. (2005) Interactions of Lysozyme in Guanidinium Chloride Solutions from Static and Dynamic Light-Scattering Measurements. Biotechnology and Bioengineering, 90, 482-490.

[6]   Rabbani, G., Kaur, J., Ahmad, E., Khan, R.H. and Jain, S.K. (2014) Structural Characteristics of Thermostable Immunogenic Outer Membrane Protein from Salmonella enterica serovar Typhi. Applied Microbiology and Biotechnology, 98, 2533-2543.

[7]   Papish, A.L., Tari, L.W. and Vogel, H.J. (2002) Dynamic Light Scattering Study of Calmodulin-Target Peptide Complexes. Biophysical Journal, 83, 1455-1464.

[8]   Nobbmann, U., Connah, M., Fish, B., Varley, P., Gee, C., Mulot, S., Chen, J., Zhou, L., Lu, Y., Shen, F., Yi, J. and Harding, S.E. (2007) Dynamic Light Scattering as a Relative Tool for Assessing the Molecular Integrity and Stability of Monoclonal Antibodies. Biotechnology and Genetic Engineering Reviews, 24, 117-128.

[9]   Hanlon, A.D., Larkin, M.I. and Reddick, R.M. (2010) Free-Solution, Label-Free Protein-Protein Interactions Characterized by Dynamic Light Scattering. Biophysical Journal, 98, 297-304.

[10]   Rubin, J., Miguel, A.S., Bommarius, A.S. and Behrens, S.H. (2010) Correlating Aggregation Kinetics and Stationary Diffusion in Protein-Sodium Salt Systems Observed with Dynamic Light Scattering. The Journal of Physical Chemistry B, 114, 4383-4387.

[11]   Grimsley, G.R. and Pace, C.N. (2004) Spectrophotometric Determination of Protein Concentration. Current Protocols in Protein Science, 33, 3.1.1-3.1.9.

[12]   Wen, J., Arakawa, T. and Philo, J.S. (1996) Size-Exclusion Chromatography with On-Line Light-Scattering, Absorbance, and Refractive Index Detectors for Studying Proteins and Their Interactions. Analytical Biochemistry, 240, 155-166.

[13]   Hisatomi, O., Takeuchi, K., Zikihara, K., Ookubo, Y., Nakatani, Y., Takahashi, F., Tokutomi, S. and Kataoka, H. (2013) Blue Light-Induced Conformational Changes in a Light-Regulated Transcription Factor, Aureochrome-1. Plant Cell Physiology, 54, 93-106.

[14]   Gekko, K. and Noguchi, H. (1979) Compressibility of Globular Proteins in Water at 25C. The Journal of Physical Chemistry, 83, 2706-2714.

[15]   Gekko, K. and Hasegawa, Y. (1986) Compressibility-Structure Relationship of Globular Proteins. Biochemistry, 25, 6563-6571.