305 



Amino Acids and Related Compounds 



TABLE VI — Continued 

 Free Amino Acids in Exponentially Growing Sfaphylococcus aureus Cells Crowing in S/nfhef/c 



Medium 



Amino Acid 



Alanine 



Cystine and cysteine 



Serine , 



Glycine 



Tyrosine 



Lysine < 



Arginine ■ 



Histidine , 



Phenylalanine 



Threonine , 



Tryptophan , 



All the amino acids found in the internal protein of the cell 

 were present in the internal pool of free amino acids. 



A new amino acid, S-methyl-L-cysteine, has been isolated 

 from Neurospora crassa.'^*' An isomer of ^-methyllanthionine 

 has been isolated from yeast." Urocanic acid has been detected 

 in Micrococcus lysodeikticus}^ 



CHa— S— CH2— CH— COOH 



NHo 

 S-Methylcysteine 



HOOC— CH— CH2— S— CH— CH— COOH 



NHo CH3 NH2 



/3-Methyllanthionine 



HOOC— CH—CH— COOH 



NH2 NH2 

 a,/3-Diaminosuccinic Acid 



New, partially characterized a-amino acids have been isolated 

 from boletus and lactarius species. ^'''' ^"^ -^ a,/3-Diaminosuccinic 

 acid has been isolated from production filtrates of the antibiotic 



^•^ James B. Ragland and James L. Liverman, Arch. Biochem. and 

 Biophys. 65 574 (1956). 



"PhyUis F. Downey and Simon Black, /. Biol. Chem. 228 171 

 (1957). 



'^^ Jana Gregoire and Jean Gregoire, Compt. rend. 245 2553 (1957). 



^^ A. I. Virtanen and O. Ayrapaa, Suomen Kern. SIB 190 (1958). 



20 Atsushi Komamine and Artturi I. Virtanen, Acta Chem. Scand. 

 13 2141 (1959). 



21 J. Casimir and Artturi I. Virtanen, ibid. 13 2139 (1959). 



