TY - JOUR
T1 - Diffusion coefficients of proteins in carrier ampholyte versus immobiline gels
AU - Gelfi, Cecilia
AU - Bossi, Maria Luisa
AU - Righetti, Pier Giorgio
PY - 1987
Y1 - 1987
N2 - The apparent diffusion coefficients of proteins in carrier ampholyte isoelectric focusing (CA-IEF) and in immobilized pH gradients (IPGs) are strongly dependent on the amount of buffering ions present in the system. However, whereas in CA-IEF increased levels of ampholytes facilitate diffusion, in IPGs they strongly quench it. It is concluded that a protein in an IPG matrix is isoelectric but not isoionic, in the sense that it forms a salt with the surrounding ions bound to the polyacrylamide matrix. This salt formation is beneficial as it greatly increases protein solubility at the pI. It is suggested that, when performing zymograms in situ, the IPG gel should contain at least twice the standard amount of Immobiline, so as to keep sharp enzyme bands even with prolonged incubation periods.
AB - The apparent diffusion coefficients of proteins in carrier ampholyte isoelectric focusing (CA-IEF) and in immobilized pH gradients (IPGs) are strongly dependent on the amount of buffering ions present in the system. However, whereas in CA-IEF increased levels of ampholytes facilitate diffusion, in IPGs they strongly quench it. It is concluded that a protein in an IPG matrix is isoelectric but not isoionic, in the sense that it forms a salt with the surrounding ions bound to the polyacrylamide matrix. This salt formation is beneficial as it greatly increases protein solubility at the pI. It is suggested that, when performing zymograms in situ, the IPG gel should contain at least twice the standard amount of Immobiline, so as to keep sharp enzyme bands even with prolonged incubation periods.
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U2 - 10.1016/S0021-9673(01)94375-4
DO - 10.1016/S0021-9673(01)94375-4
M3 - Article
C2 - 3571371
AN - SCOPUS:0023658754
VL - 390
SP - 225
EP - 236
JO - Journal of Chromatography A
JF - Journal of Chromatography A
SN - 0021-9673
IS - 2
ER -