Determination of Measles Virus Protein Molecular Weights on High Percentage, Highly Cross-Linked SDS Polyacrylamide Gels

Abstract

The electrophoretic m ig ratio n o f an S D S -p ro tein com plex is affected b oth by the am o u n t o f SDS bound (i.e. charge) and by th e m o lecu lar sieving effect o f the gel mesh. T he latter is governed by th e cross-linking w ithin th e gel, and B ay reu th er et al. [8] have hown th at the sieving effect can p red o m in ate in high percentage poly acry lam id e gels w ith a low acry lam id e/b isacry lam id e ratio. In the case o f lac tose perm ease, an ap p a ren t m o lecu lar w eight o f 30 K d eterm ined by electrophoresis on a 10% p oly acrylamide gel (a c ry la m id e :b isa cry la m id e= 3 7 .5 :1) was increased by over 50% to 46.5 K if electro phoresis was perfo rm ed on a 20% gel o f th e sam e acry lam id e:b isacry lam id e ratio. Since th e true m olecular w eight o f this p ro tein was know n from D N A sequence to be 46.5 K [11], this p ro ce d u re for m olecular w eight d eterm in a tio n effectively o ver comes errors due to increased SDS binding. T he measles virus M p ro tein m o lecu lar w eight has been determ ined from SDS gels as 3 7 -4 0 K. Exact inUnauthenticated