Protection of Synaptic Transmission Against Block by Nicotine

Abstract

Soybean meal was digested by papain at 50[degree]C for 48 hrs. This sample and a control, containing a boiled soln. of the enzyme, were dried. The inhibitor was partially destroyed. A requisite amt. of inhibitor soln. was added to both extracts to restore the original activity. The biologic value of the digested sample was 45.9 and its digestibility coeff. was 89.6; the biologic value of the control was 44.7 and its digestibility coeff. was 89.2. In the digested sample, 91.6% of the total N of the meal was in the nonprotein form, and 90% of the total methionine of the protein was in the free form. The results showed that the role of the proteolytic inhibitor in deciding the nutritive value of raw soybean was not in decreasing the degree of availability or rate of release of methionine. There might be other toxic factors associated with the raw bean which were destroyed on heating. The growth-promoting value of soybean protein increased markedly if the bean was germinated. The conc. of the proteolytic inhibitor in the germinated soybean was not changed from that in the original bean. The concept of the proteolytic inhibitor could not explain this increase in nutritive value after germination.