752 VII. LIPID DISTRIBUTION IN SPECIFIC TISSUES 



The enzyme appears to be essentially a butyrylcholinesterase, and re- 

 sembles the pseudoenzyme of human plasma. More of the enzyme was 

 present in the white matter than in the gray matter. It is suggested that 

 the action of this enzyme may be related to processes occurring in the 

 myelin sheaths or connective tissue, rather than to those of the axis cylin- 

 ders. 



(d) Sulfolipids. Thudichum, 220 as early as 1884, reported the presence 

 of a sulfur-containing lipid in a phrenosine mixture obtained from brain. 

 The sulfur content was of such magnitude as to preclude the possibility 

 that it was an impurity. The purified product of Thudichum had a sulfur 

 content of 6.19%. At a later date, Koch 270 prepared a sulfate from the 

 ether-insoluble residue which contained not only sulfur (1.91%) but also 

 phosphorus (1.80%) and sugar (12.8%). Because of the parallelism be- 

 tween the sulfur and the sugar content, Koch assumed that the sulfuric 

 acid formed an ester with the alcohol groups of the sugar. Frankel and 

 co-workers 271 ' 272 likewise reported the preparation of two sulfur-containing 

 lipids, called "Hirnsaure" (brain acid), and "Hypohirnsaure," which they 

 obtained by Thudichum's method. The two preparations contained 1.86 

 and 1.70% of sulfur, respectively. Levene 273 prepared a sulfatide from 

 brain which was phosphorus-free, but which contained 2.66% sulfur. 

 Later, with Landsteiner, 274-276 he isolated a sulfur-containing lipid from the 

 protagon of brain and kidney which yielded 1.32% S on analysis. These 

 experimental results are sufficiently confirmatory to convince one that sul- 

 fatides exist in nervous tissue. 



Subsequently, Blix 277 extended the earlier observations by a compre- 

 hensive study of the lipids in human brain. This investigator was able to 

 isolate cerebron-sulfuric acid, as the potassium salt, in the amount of 20 

 to 25% of the total cerebrosides. The potassium-cerebron-sulfuric acid 

 was assumed to have an empirical formula of C48H92NSO12K; the composi- 

 tion of this compound, as determined by hydrolysis, agreed well with the 

 theoretical values for a molecule made up of one part each of fatty acid 

 (cerebronic), 40.7%, sphingosine, 31.6%, galactose, 19.0%, sulfuric acid, 

 10.4% and potassium, 4.1%. 



270 W. Koch, Z. physiol. Chem., 70, 94-97 (1910). 



271 S. Frankel and O. Gilbert, Biochem. Z., 124, 206-215 (1921). 



272 S. Frankel and O. Karpfen, Biochem. Z., 157, 414-424 (1925). 



273 P. A. Levene, /. Biol. Chem., 13, 463-464 (1912). 



274 K. Landsteiner and P. A. Levene, J. Immunol, 10, 731-733 (1925). 



275 K. Landsteiner and P. A. Levene, Proc. Soc. Exptl. Biol. Med., 23, 343-344 (1926); 

 24, 693-695 (1927). 



276 P. A. Levene and K. Landsteiner, J. Biol. Chem., 75, 607-612 (1927). 



277 G. Blix, Z. physiol. Chem., 219, 82-98 (1933). 



