Molecular weight analysis of oligopeptides by electrophoresis in polyacrylamide gel with sodium dodecyl sulfate.

Physical factors leading to the separation of oligopeptides in the molecular weight range of 1,200 to 10,000 daltons by analytical-scale electrophoresis in polyacrylamide gel with sodium dodecyl sulfate are described. Increased acrylamide concentration, cross-linkage, and inclusion of 8 M urea to decrease gel porosity, increased gel length, and buffer ions of low mobility are factors which yield improved separation of such peptides. Electrophoretic mobilities of eleven peptides were linearly related to the logarithm of their molecular weights with a standard deviation of 18% in a system of improved resolution. The intrinsic charge and conformation of peptides were found to be relatively more important determinants of electrophoretic mobilities than for proteins larger than 10,000 daltons. Such determinants were relatively more important with four of the eleven peptides examined, leading to deviations from the log-linear slope greater than 18%. Because of the importance of intrinsic charge and conformation, the system, although allowing a first approximation in molecular weight determination, may also be applicable to peptide “mapping,” particularly for “insoluble” peptide mixtures with prominent hydrophobic association, such as encountered in cellular membranes, viruses, and proteolytic digests.

[1]  G. K. Ackers.  MOLECULAR EXCLUSION AND RESTRICTED DIFFUSION PROCESSES IN MOLECULAR-SIEVE CHROMATOGRAPHY. , 1964, Biochemistry.

[2]  T. Laurent,et al.  A theory of gel filtration and its exeperimental verification , 1964 .

[3]  H. Noller,et al.  Ribosomal proteins of Escherichia coli. II. Proteins from the 30 s subunit. , 1968, Journal of molecular biology.

[4]  E. Bradbury,et al.  A conformational study of glucagon. , 1968, European journal of biochemistry.

[5]  J V Maizel,et al.  Molecular weight estimation of polypeptide chains by electrophoresis in SDS-polyacrylamide gels. , 1967, Biochemical and biophysical research communications.

[6]  P. Butler,et al.  The use of maleic anhydride for the reversible blocking of amino groups in polypeptide chains. , 1969, The Biochemical journal.

[7]  J. Steinhardt,et al.  Binding-induced alterations in ultraviolet absorption of native serum albumin. , 1968, Biochemistry.

[8]  R. Pitt-Rivers,et al.  The binding of sodium dodecyl sulphate to various proteins. , 1968, The Biochemical journal.

[9]  K. Weber,et al.  The reliability of molecular weight determinations by dodecyl sulfate-polyacrylamide gel electrophoresis. , 1969, The Journal of biological chemistry.

[10]  P. Berg,et al.  Isoleucyl transfer ribonucleic acid synthetase is a single polypeptide chain. , 1970, The Journal of biological chemistry.

[11]  T. Jovin,et al.  Fractionation of oligodeoxynucleotides by polyacrylamide gel electrophoresis. , 1969, Analytical biochemistry.

[12]  A. Dunker,et al.  Observations on molecular weight determinations on polyacrylamide gel. , 1969, The Journal of biological chemistry.

[13]  K. J. Monty,et al.  Determination of molecular weights and frictional ratios of proteins in impure systems by use of gel filtration and density gradient centrifugation. Application to crude preparations of sulfite and hydroxylamine reductases. , 1966, Biochimica et biophysica acta.

[14]  S. Colowick,et al.  Methods in Enzymology , Vol , 1966 .

[15]  J. S. Fawcett,et al.  Molecular-Sieve Chromatography of Proteins on Granulated Polyacrylamide Gels , 1966 .

[16]  M. Tombs,et al.  Mobility-molecular weight relationships of small proteins and peptides in acrylamide-gel electrophoresis. , 1967, Analytical biochemistry.

[17]  J. Maizel,et al.  Molecular weight estimation of polypeptides by SDS-polyacrylamide gel electrophoresis: further data concerning resolving power and general considerations. , 1969, Analytical biochemistry.

[18]  A. Smith,et al.  Size and charge isomer separation and estimation of molecular weights of proteins by disc gel electrophoresis. , 1968, Archives of biochemistry and biophysics.

[19]  E. G. Strauss,et al.  Acrylamide gel electrophoresis of bacteriophage Q beta: electrophoresis of the intact virions and of the viral proteins. , 1970, Virology.