n8 Scientific Proceedings (66). 



72 (1004) 



Comparison of certain properties of pancreatic and malt amylase 



preparations. 



By H. C. Sherman and M. D. Schlesinger. 



[From the Laboratory of Food Chemistry, Columbia University.] 



The amylase preparations made from pancreas and from malt 

 are similar in many respects but are not identical substances. 



Both are essentially protein materials, showing typical re- 

 actions in the Millon, xanthoproteic, tryptophan and biuret tests, 

 containing 15 to 16 per cent, of nitrogen, and yielding the different 

 types of amino acids distinguishable by the Van Slyke method in 

 proportions similar to those found in typical proteins by Dr. Van 

 Slyke. 



Both the pancreatic and the malt amylase preparations when 

 heated in solution yield coagulated albumin and a proteose or 

 peptone. 



These and other observations are in harmony with Osborne's 

 theory of the chemical nature of the enzyme, and not with the 

 findings of Frankel and Hamburg or of Pribram. 



Malt amylase is most active in a somewhat acid solution 

 (P# 4.4 ± 0.2) whereas the optimum for pancreatic amylase is 

 slightly alkaline. 



Among the best preparations obtained in a long series of 

 purification experiments the pancreatic is more than twice as 

 active as the malt amylase. In 30 minutes at 40 0 the former 

 produced 10,000 times, the latter 4,000 times, its weight of maltose. 

 When allowed to act at the same temperature until no further 

 action could be observed the pancreatic amylase preparation 

 digested 2,000,000 times its weight of starch and produced 

 1,200,000 times its weight of maltose. 



The most highly purified pancreatic amylase preparations show 

 also a pronounced proteolytic action, while the corresponding 

 malt amylase preparations show no proteolytic activity. 



The results of the investigation are being published in a series 

 of papers in the Journal of the American Chemical Society. 



