In the course of developing the packaging of protein foods under the carbon dioxide atmosphere, various proteins in a solid state were found to adsorb carbon dioxide gas gradually. The results obtained by the Warburg manometry indicated that 100-1, 000μl of carbon dioxide gas was adsorbed at 25°C for 24 hr by gram of purified proteins, dried protein foods and otherr proteinous materials such as the rabbit hair and raw silk when they were placed in the high partial pressure of carbon dioxide gas. Casein, gelatin and raw silk were revealed to be the better adsorbents comparing with egg albumin, hemoglobin, gluten and others tested in this experiment. This adsorption was found to be almost specific to carbon dioxide gas. Amount of carbon dioxide gas adsorbed by casein and gelatin depended on the moisture content of them. The lower the moisture is, the greater the adsorption amount of carbon dioxide gas increase. Peptones and partial hydrolyzates of gelatin also showed the adsorbability. Oligo-peptides, amino acids and aminess were examined too. Among these, L-lysine (free base), L-arginine (free base), histamine and tyramine adsorbed a large amount of carbon dioxide gas while others failed to do so. Some differences, however, were observed between temperature dependence and reversibility of the carbon dioxide gas adsorption by proteins and those by amines and amino acids (free bases). The mode of interaction between carbon dioxide and protein in a gas-solid phase was discussed comparing with the results obtained in a gas-liquid phase. Large contribution of physical adsorption and less contribution of chemical reaction or chemisorption were assumed in the mode of the carbon dioxide-protein interaction.
Susceptibility to some antagonists of vitamin B6 was studied in frogs and cockroaches after operational intervention in their central nervous systems, and also in the intact frogs and cockroaches. Thiosemicarbazide, semicarbazide, isoniazide and penicillamine induced wild jumping behavior, and tonic or clonic convulsions in frogs, when the nervous parts posterior to the optic lobe inclusive remained intact. In frog, in which the nervous parts anterior to the diencephalon inclusive had been removed, no convulsions were induced by castrix or 4-deoxy-pyridoxine in large doses. In cockroaches excessive fluttering of wings and convulsions upon administration of thiosemicarbazide following severance of the central nerve cord between the subesophageal and prothoracic ganglions were induced. Castrix was not a convulsant in the intact frogs and cockroaches.
TTP accelerated ATP-induced superprecipitation of actomyosin in as low a concentration as 30μM and decreased light scattering by actomyosin. These effects could also be observed in the same way, but to a lesser degree, by addition of TDP. Myosin was able to hydrolyze TTP to TDP, but some important differences were confirmed between myosin TTPase and ATPase. Myosin TTPase was inhibited by actin and showed a much larger Km than that of ATPase. TTP significantly inhibited myosin B ATPase and ATP greatly inhibited myosin B TTPase. These findings suggest that the accelerating effect of TDP and TTP may be due to the binding of thiamine phosphate to the regulatory site of myosin followed by a change in its physical chemical property, rather than due to the competitive binding of thiamine phosphate to the catalytically active site of myosin.
A high-speed liquid chromatographic method for the determination of α-, β-, γ- and δ-tocopherols using a spectrophotometer or a spectrofluorometer, is described. The best results were obtained using a 2.3 mm i.d.×500mm normal phase partition column, JASCO-PACK WC-03-500 and a spectrofluorometer as a specific detector. A mixture of diisopropyl ether and n-hexane (2:98) was used as the mobile phase. A flow rate was set at 0.8ml/min. A mixture of pure α-, β-, γ- and δ-tocopherols or natural tocopherols in vegetable oils were separately determined by this method.
Thiamine pyrophosphokinase (EC 18.104.22.168) from parsely leaf showed an absolute requirement for divalent cation such as Mg2+, Mn2+ and Co2+. The activation effect varied with the species and concentrations of such cations. When Mn2+ or Co2+ was used as cofactor, maximal activation was found at a lower level than ATP concentration, whereas the activation by Mg2+ increased hyperbolically with the concentration. Studies of initial velocity and product inhibition led to conclude that the kinase reaction obeys a sequential ordered Bi Bi mechanism; i.e. the enzyme combines in turns with MgATP and thiamine, followed by release of TPP and AMP. The inhibition type revealed for inorganic pyrophosphate was competitive with respect to thiamine with Ki of approximately 2.8mM. On the other hand, thiamine monophosphate exhibited noncompetitive inhibition with Ki of 0.2mM. The plots of the reaction rate against MgATP concentrations gave a sigmoidal curve. Addition of either AMP or GMP resulted in restoration of a depressed activity at low concentration of MgATP. The “allosteric” inhibition was also relieved by the addition of an excess amount of magnesium ions. These findings suggest that transphosphorylation is regulated by subcellular concentrations of metal ions relative to ATP or of the products involved in the thiamine biosynthesis.
A squirrel monkey, if it needs a particular dietary component because of a metabolic disorder or because that food has been excluded from its diet, will develop a specific hunger for the food. In cases where specific hungers show up clearly, four behaviors can be demonstrated: (1) The monkey prefers the food it needs to other foods that are also available; (2) It usually ingests large amounts of the food to meet its particular physiological requirements; (3) The animal will tend to eat the needed food even while its stomach is full; (4) When vitamin B2 is removed from its diet, a squirrel monkey will exhibit digestive disturbance, general weakness, a lack of vigor, and loss of weight.
The effect of diets containing various amounts of casein and starch on enzymes bound to the brush border of the small intestine and kidney of rats were investigated with the following results. 1) Diets with low starch and high casein contents resulted in higher specific activity of leucineaminopeptidase in the small intestine than diets with high starch and low casein contents. Diets with high starch and low casein contents increased the specific activity of maltase. 2) Rat small intestine contains at least two isoenzymes of leucineaminopeptidase: one bound to the brush border and the other not bound to it but recoverable in the soluble fraction. Only the former was influenced by the diet. 3) The maximum velocity (Vmax) of leucineaminopeptidase bound to the brush border was twice as much in rats on a high casein diet as in those on a low casein diet, but the Michaelis constant (Km) was approximately the same in both groups of rats. 4) Leucineaminopeptidase and maltase activities in the kidney were not influenced by diet.
Twenty-four female rats consisting of 6 sets of litters were used for the experiment. After weaning, rats were divided into 4 groups and fed with 10, 18, 27 and 36% casein diet. Effect of protein nutrition on aging was examined from the anthropometric and biochemical viewpoint. The difference of growth in body weight, and that of the urinary excretion of creatinine and 17-ketosteroids observed in the early period of growing disappeared by the end of growth period. From 1 year after birth, serum alkaline phosphatase activity and serum cholesterol were also measured. However, effect of protein nutrition on these parameters was not clear due to the scatter of data. The difference in diet did not affect life span in the present experiments, but the effect of the variance of litters on it seemed to be significant between the rats fed 18% casein diet and those fed 10% casein diet. Rats fed high-protein diet had a great number of lesions in the kidney and hypophysis, and often an incidence of tumors.
The effect of overnight fasting on glycerolipids of the rat liver organelles was studied. The concentration of microsomal phospholipids was markedly decreased by fasting, whereas that of mitochondria and whole liver increased significantly. The significant increase due to fasting in the activity of microsomal phosphorylcholine-glyceride transferase appeared to be responsible for the increased concentration of hepatic phospholipid. The incorporation by the liver slice of [l-14C] glycerol into PC3 in mitochondria was increased by fasting, while there was no difference in the microsomal fraction containing supernatant. The significant decrease in the relative proportions of oleic and linoleic acids and a significant increase in stearic and arachidonic acids in phosphatidylcholine were observed in the intact liver as well as its subcellular fractions. The possible relationship of these changes after fasting to the similarity in the incorporation pattern of [l-14C] glycerol into the molecular species of these glycerolipids was demonstrated.