ISSN:
1471-4159
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Medicine
Notes:
During sodium dodecyl sulfate polyacrylamide gel electrophoresis of sciatic nerve myelin proteins, the P0 protein migrated to two different positions on the gels. The distribution of P0 between the two forms depended on the concentration of mercaptoethanol (ME) or dithiothreitol (DTT) in the sample solvent. At 〉1% ME or 3.5% DTT, P0 was almost entirely in a form with an apparent molecular weight of 30,000, whereas in the absence of ME or DTT all the P0 migrated with an apparent molecular weight of 25,000. The distribution of the P0 protein between the two bands was independent of whether proteinase inhibitors were used during preparation of myelin. Furthermore, in a sample containing the more rapidly migrating form of P00, the P0 could be converted to the slower-migrating form by addition of mercaptoethanol. These data show that interconversion of the two forms of P0 does not involve proteolytic degradation, but suggest rather that ME cleaves one or more intramolecular disulfide bonds in P0 unfolding the amino acid chain and thereby converting the form with a lower apparent molecular weight to that with a higher apparent molecular weight. We postulate that the “Y” protein band, which has been observed, in variable quantities, migrating slightly ahead of P0, may represent its oxidized form.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1471-4159.1980.tb06610.x
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