1. Raw soya-bean meal (RS) was fractionated into soya-bean lyophilized extract (SLE), soya-bean lyophilized residue (SLR), acid-precipitated proteins (APP) and whey proteins. 2. Trypsin (EC 3. 4. 21. 4)and chymotrypsin (EC 3. 4. 21.1) inhibitors (TI) were soluble at pH 8 and remained soluble after the extract was acidified to pH 4.4 Except for whey, heating abolished, almost totally, their inhibiting activity. 3. Feeding SLE diet (high TI content) and APP diet (low TI content) resulted in growth depression below the RS level. Feeding the SLR diet resulted in an optimal growth. Feeding diets containing heated fractions improved the growth rate though not to the level observed with heated RS (HS) diet. 4. RS, SLE, APP and whey diets produced similar pancreatic enlargement which could be totally (RS, whey) or partially (SLE, APP) abolished by heating. 5. Feeding the RS diet reduced pancreatic amylase content. The factor responsible for this effect cofractionated with SLE and whey proteins. 6. Two groups of factors in the various diets were probably responsible for the elevation in pancreatic proteases. The first group were the heat-labile factors present in RS, SLE and whey whereas the second group resisted the heat treatment and were found in APP and SLR. 7. The results suggest that for optimal growth rate of rats, heat treatment should be given to the unfractionated soya-bean proteins rather than to the isolated fractions. The results further indicated that TI are not the only factors that can lead to pancreatic enlargement and changes in pancreatic enzymes composition.
Summary TWO levels of roughage, 3 FU (feed units) and 5 FU daily, were fed to Israeli?–Friesian cows and heifers receiving either a normal (Normal) or a high-energy (High) diet. Milk yield and composition were examined for 12 weeks following parturition. The animals receiving 5 FU of roughage daily showed a higher milk yield during the first 8 weeks. With the Normal diet the amount of roughage had no effect on milk composition. With the High diet, milk yield was higher than with the Normal, and a depression in fat percentage was observed in the milk of cows and heifers receiving 3 FU daily. No corresponding fall in milk protein percentage was observed – the cows of this group (High-3 FU roughage) showing, in fact, a rise in protein percentage. No differences in milk total solids were found. With these high-energy low-roughage diets no correlation was apparent between milk fat and protein percentages.
Inhibitors of animal, plant, and microbial origin were tested against human and canine granulocytic elastases. The trypsin-chymotrypsin inhibitors from dog submandibular glands, from soybeans (Bowman-Birk) and from chickpeas show strong interaction with these proteases (Ki = 10(-8) - 10(-9)M). The trypsin-kallikrein inactivator of bovine organs (Trasylol) is not active against granulocytic elastases or against human granulocytic cathepsin G. Elastatinal, a specific inhibitor of elastases, isolated from actinomycetes (Streptomyces griseoruber), forms stable complexes with elastase from human (Ki = 6.2 X 10(-6)M) and canine granulocytes (Ki = 1.1 X 10(-6)M). A possible therapeutic application of these inhibitors for the inactivation of granulocytic proteases, which are able to degrade connective tissue in different pathological states, is discussed.
Abstract A sapogenin isolated from the acid hydrolysates of roots or tops of alfalfa (Medicago sativa) has properties and constants identical to those of hederagenin. The corresponding saponin was isolated from a mixture of alfalfa saponins by successive chromatography on Al 2 O 3 and DEAE‐Sephadex columns. Upon acid hydrolysis it yields glucose, arabinose and hederagenin, similarly to the saponin isolated from Hedera helix.
Circular dichroism spectra of trypsin‐chymotrypsin inhibitors from soybeans and chickpeas have been determined in acidic, neutral and highly alkaline solutions. Neither protein contains α‐helix although a small amount ofβ‐structure cannot be excluded. Negative dichroism above 250 nm has been assigned largely to disulfide bonds in both molecules with neither showing evidence for tyrosine residues buried in hydrophobic regions. The spectra of these inhibitors between 230 and 250 nm have been compared with the spectra of a number of structurally related proteins suggesting that previous interpretations of this region may have been incomplete or incorrect.
