Some controversial views have appeared regarding the content of proteins inmushrooms (SmotIacha, 1947, S a n d e v and D u s h e v , 1963, P i l i t , 1965). As a part of this problem, to investigate the composition of protein fractions we carried out electrophoresis of mushroom extracts' in a 7.5% acrylamide gel.Freshly gathered mushrooms in amounts of about 100 g were homogenized in a turmix with equal weights of a 1% NaCl solution to maintain the proteins in solution. Centrifugation at 10000 g for 10 min yielded a n opalescing supernate. This extract, like some plant extracts (S t e w a r d and B a r b e r , 1964), inhibited photopolymerization of acrylamide. W e therefore used our own procedure for introducing the samples. W e placed about 50-150 pl of the fluid extract on the spacer gel, covered it with the buffer used and stoppered carefully in a glass tube (5 X 65 mm) with a specially prepared 3 mm thick acrylamide cylinder. This procedure proved suitable for all samples which inhibit polymerization, e. g. haemoglobin solutions.As differences occurred between the results obtained with lyophilized and fresh extracts, only the latter were used throughout this work. I n the initial stages no quantitative protein determinations were made on the mushroom extracts, and therefore on account of the wide range of protein concentrations, series of extracts of increasing volume were analyzed electrophoretically.Electrophoresis was carried out in a usual manner (0 r n s t e i n and D a v i s 1962) with a tris-hydroxymethyl-aminomethane-glycine buffer of pH 8.6. T h e current was regulated to 4 mAmp.lcolumn. In the course of electrophoresis the pigments present i n the extracts moved toward the anode and separated into 2-4 fractions, blue, yellow or brown, red or black in . colour. T h e electrophoresis was stopped after 90 min when the fastest pigment fractions had approached to about 5 mm from the anode end of the gel.T h e proiein fractions were stained with Amido Black 10 B. I n the course of staining and de-staining some pigments escaped the gel, but there remained, nevertheless, one or two zones, which were probably formed by pigmented proteins and which revealed the highest electrophoretic mobility.Evaluation of stained protein fractions was carried out directly in situ a t 570 W L by means of a Unicam SP. 500 spectrophotometer equipped with a SP. 590 strip-scanning attachment ( B e n n e t t , 1962). Readings, made every 0.5 mm or less, served for the construction of curves.T h e electrophoretic separation itself, as well as evaluation which followed, was eminently reproducible, as we proved by duplicate analyses carried out in two different laboratories with different mushroom samples.W e analyzed a total of 31 mushroom species and found some relations, the study of which will be extended in future. In repeated series of analyses indi-Downloaded by: University of Victoria. Copyrighted material.
