222 



MACROMOLECULAR COMPLEXES 



amino acids. These findings hold for both the low-protein bakers' 

 yeast and the high-protein strain {Saccharomijces cerevisiae, 18.29). 

 Quantitative determinations on the amino acid composition of the 

 protein components have been carried out on the three fractions; 

 values for the recoveries of the principal amino acids are shovi^n in 

 Table 3. These figures reveal that the proteins associated with the 



TABLE 3 

 Amino Acid Analysis of Cell Wall Components * 



Amino Acid 



Glucan-Proteint 



GMP-II 



GMP-IIt 



Glutamic acid 10.9 17.8 9.2 



Aspartic acid 29.8 13.1 31.1 



Cvsteic acid 1.5 0.2 8.4 



Tyrosine 2.2 5.0 2.7 — 



Serine 4.1 4.1 4.6 



Threonine 6.0 5.0 5.9 



Glycine 3.3 3.5 4.6 



Alanine 6.4 6.9 6.5 



Valine 6.5 4.6 5.4 



Proline 7.8 2.2 



Methionine 1.6 



Isoleucine 4.5 5.1 4,9 



Leucine 4.6 9.1 7.0 



Lysine 5.1 8.1 6.2 



Histidine 2.7 



Arginine 3.7 7.2 3.5 



Phenylalanine 3.6 3.8 



' Values expressed as percentages of total recovery from acid hydrolysates of each 



component; from data of Kessler and Nickerson (1959). 



t Glucan-protein isolated from bakers' yeast. 



\ Glucomannan-proteins I and II isolated from strain 18.29 of Soccharoimjces 

 cerevisiae. 



three fractions are highly acidic; glutamic and aspartic acids, to- 

 gether, account for 31 per cent (GMP-I), 35 per cent (GP), and 39 

 per cent ( GMP-II ) of the total recovery. Although total recoveries 

 of approximately 75 per cent of the amino acid components were 

 obtained for GP and GMP-I, it must be borne in mind that some 

 destruction and alteration of amino acid residues could not be 

 avoided under the conditions used for the protein hvdrolvsis; trypto- 

 phan, if present, would have been completelv destroyed. 



Configuration of Polysaccharides in Wall Components. Im- 

 munochemical studies on the cross-reactions of glucomannan-pro- 



