AN ISOANTIGENIC LIPOPROTEIN 83 



different from those found for TSL in the presence of Triton. 

 However, since Triton may influence the mobihties, no conclu- 

 sions can be drawn from such a comparison. The minor com- 

 ponent in Fig. 6 may therefore represent a minor contaminant of 

 TSL not detected by electrophoresis in the presence of Triton. 

 It is, however, at least as likely that the minor component in Fig. 6 

 may represent that portion of TSL not altered by the venom 

 enzyme, or some venom protein co-precipitated with the altered 



ASCENDING DESCENDING 



-^ 37min. -> 70 min. 70 min. < 



Fig. 6. Tracings of electrophoretic patterns of material 

 isolated from a snake venom digest of TSL. Electro- 

 phoresis was in barbitone buffer pH 8 • 6, [i,= o • i . The field 

 strength was 13 volts/cm. The concentration of protein 

 was I • 3 per cent. Mobilities of the two components were 

 — 8-25x10"^ and —5-33x10"^ cm.^ sec.~^ volt~\ 

 respectively. 



TSL. Estimated from its mobility at pH 6*3 and 8*6 the iso- 

 electric point of the major component was essentially the same as 

 that for unaltered TSL. As shown in Fig. 7, venom-digested TSL 

 appeared to inhibit red cell haemagglutination somewhat more 

 effectively than did the unaltered material. 



Although much more work is required to establish fully the 

 purity and structure of the TSL and of the more soluble derivative 

 produced by digestion with snake venom, it seems probable that 

 these goals will be reached. The isolation of these substances, 

 however, raises further questions concerning the relationships of 

 their molecular structures to the minimum structural features 



