AMINO ACIDS AND DERIVATIVES IN DROSOPHILA I43 
wild-type pattern has been shown to be quite reproducible and the pattern from 
another mutant (/-2r) did not differ significantly from that of the wild type. 
The differences observed in Fraction 3 are less obvious as presented here than from 
observations of paper chromatograms. The most striking one is at tubes No. 98 and 
99 where mutant /-me appeared to be totally deficient in one peptide component (of 
approx. 20 residues) that is found in wild, /-tv and /-2r. 
At present only one substance involved in one of the major differences pointed out 
above has been identified. This appears, with poor resolution on Dowex-50, in tubes 
No. ro-18 and accumulation is shown in translucida. This accumulation is associated 
with the deficiency in /-tv at tubes No. 75 and 76 which is the position of tyrosine. 
The accumulation, which has been noted previously?” is due to the substance tyrosine- 
O-phosphate (Fig. 6) which has been isolated and identified by comparison with 
synthetic material. Thus, wild and /-me third instar larvae contain about equal 
amounts of tyrosine and tyrosine phosphate while /-tv contains a large amount of the 
phosphate ester and essentially no free tyrosine. 
ACIDIC PEPTIDES 

GLU:-GLY GLU:SER 


eee ly 7a aT ani earl I 
Zee eee lal It 
Cc ZENON 
GLU-GLY-ALA GLU-GLY-ASP GLU:GLY:-SER GLU:-SER:ASP 
ay RNS) 1 I ay sh a I ae hase 2 I Ay a I 
b I I I GLU:-GLY-CYS GLU-GLY:THR 
BEG i QB I a or I I 2, U@®, 9 oie I 
d I I 3 bez I I Denes I I 
om @ Bay Bir 4 
GLU-GLY-ALA-SER GLU-GLY-CYS:-PHE GLU-GLY-SER- X 
a Fi I I I a I I I 5 ay al I i Iago a 
be 4 ee x I I GEU-GE Ye AGT YRS by or I i INST! 
AM iG 2 I I Mea, a I I 2 GLU-GLY-ALA: X 
d I I I I Dees I I BU al era I Tt ONES IL 
e I 2 I I c I I I Sibert ow tar 1 NSHP) it 
c I I I I 

GEY-GRYCALA-SER- CYS (GLU-GEY-NEACASP- 2x GLU-GLY-THR:-ASP-CYS 


a 2 I I I I anes I I i (CNS) Sah Ao) I I I I 
Det 1 a ae ey Be gh a IER ey Gn 2 I I 
c 3 I 3 SBC ae I I 2 I I 
5 GLU-GLY-ALA-ASP-PROd 4 I i dMalgear (CONaS 
a Ci vi I I I E- © i AL geste I 
b 3 I I I I 
6 GLEU-GLY-THR-ASP-CYS:-PRO 
an er I I I I I 


Fig. 7. Composition of some acidic peptides from Drosophila larvae. These represent a small 
proportion of the total number present in larval extracts and not a random sample. The amino 
acid order given has no significance since only compositions have been determined. Proportions 
are only approximate for the peptides with many repeats of the same amino acid. 
References p. 146 
