Quantitative electrophoretic study of rabbit muscle proteins soluble in dilute salt solutions

Abstract

The quantitative aspects of the electrophoresis of the muscle proteins of the myogen-globulin-X group, soluble in dilute salt solutions, were studied.

The most sensitive method of detecting differences between diagrams appears to be visual inspection of superposed projections (magnification 10-fold to a base length of 34.5 cm).

With respect to symmetry of the diagrams, the number of details detectable in the diagrams and the time required for full development along the basis of the diagrams, a KCl-phosphate solution of pH 7.15 and ionic strength 0.13 appeared to have most adequate properties.

As the diagrams change upon aging of the extracts this solution was also used for extraction in order to shorten the time required for dialysis. With 12 hours' dialysis at 2°C and 13,000 seconds of electrophoresis diagrams could thus be obtained within 24 hours after the animal was bled in narcosis.

1 ml of this solution per g muscle was shown to provide complete extraction of the group of proteins studied.

Skeletal muscle of the rabbit gave after 13,000 seconds of electrophoresis patterns in which nine protein components could be detected, eight of these occurring in concentrations sufficiently high to permit their numerical evaluation from the diagrams. The protein components do not gradually change in number and amounts upon increasing the ionic strength of the solution used for extraction, dialysis and electrophoresis. Thus the proteins studied constitute a sharply defined class, for which the diagrams obtained may be considered to be representative.

While diagrams of extracts of various samples of one batch of muscle pulp appeared to be quite identical upon visual inspection of the superposed projections, small differences could be detected between extracts of randomly chosen different parts of the white muscle system of one rabbit. More pronounced differences appeared to exist between white muscles of different rabbits. The differences between white and red muscles of one rabbit are only small, while the smooth muscular tissue of the stomach gives a completely different pattern.