The hydrazinolysis method has been applied to the identification of C-terminals of taka-amylase A and serine, glycine and alanine were found as C-terminal amino acids. From the quantitative studies, it has been suggested that taka-amylase A may have three C-terminals against one N-terminal.
The author wishes to express his gratitude to Professor S. Akabori for his kind guidance, and to Dr. K. Ohno for his helpful advice through this investigation, and also to Sankyo Co. Ltd. for their kind supply of “Takadiastase Sankyo.” The author also wishes to thank Mr. H. Hanafusa for his assistance in ion-exchange resin chromatography.

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Chemical studies on the organ specificity were performed using
TABLE XIV Effect of Esterification of Carboxyl Groups in the Partial Hydrolysate of Eyelens Crystallin upon Its Activity as An Inhibitor
_??_
eyelens crystallin of ox, horse, and pig and the following results were obtained:
1. Sphingomyelin, cerebroside, and other lipids contained in .the eyelens are not responsible for the organ specificity.
2. α- and β-Crystallins of eyelens react specifically, but γ-crystallin does not.
3. The ability of the crystalline to react with the eyelens antiserum is lost by hydrolysis with 1 N or 5 N sulfuric acid for 0.5 or 0.3 hours, but the activity of inhibiting the serological reaction between lens crystallin and the corresponding antibodies remains intact when it was hydrolysed with 5 N sulfuric acid for one hour.
4. These partial hydrolysates scarecely show biret reaction but are not precipitated by sulfosalicylic or trichloroacetic acid, and can be dialyzed throughly collodium membran.
5. When the partial hydrolysate is coupled with diazobenzene-sulfanylic acid or the free carboxyl groups in it are esterified with ethyl groups the activities are destroyed.
6. The active substances in the partial hydrolysates of the eyelens crystallins of ox or horse can be isolated by column chromatography, and by the complete hydrolysation, they liberate several amino acids common to all, other such as serine, histidine, glutamic acid, alanine, and tyrosine.
From these facts, it may be considered that the specific substances in eyelens of animals are α- and β-crystallins and the chemical structures which is responsible for organ specificity are groups of comparatively small polypeptide residues.
The author wishes to express his most sincere thanks to prof. S. Fujimura for his kind advises through this research.

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1. The intermediary product between homoserine and threonine, synthesized enzymatically from homoserine and ATP in the presence of Mg^_??_, was isolated as barium salt and identified as O-phosphohomo-serine.
2. The over-all reaction leading to the synthesis of threonine has been formulated as homoserine→O-phosphohomoserine→threonine. The postulated pathway was also supported by the studies on phosphate transfer.

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1. Nitric oxide is produced from nitrite and is utilized in place of the latter and it is presumable that nitric oxide is an intermediate in denitrification.
2. Dimethyl-p-phenylene diamine and p-phenylene diamine can act specifically as reducing agents where the quantity of nitrogen pro-duced corresponds to about twice as much as nitrite-N.
3. Gas production with the dime thyl-p-phenylene diamine-nitrite system is inhibited by KCN and p-chloromercuribenzoate. Effects of other various inhibitors were described.
4. The essential stages in the denitrifying process were discussed.
The expences for the work were aided partly by the Scientific Research Funds and by the Grant in Aid for the Scientific Research from the Ministry of Education.

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1. From α- and β-trihydroxyhomocholenes, same keto-derivative was obtained, which means that either of trihydroxyhomocholenes has a double bond at the same position. From, β-trihydroxyhomocholene, after permanganate oxidation, 3, 7, 12-trihydroxy-14-keto-14:15-homo-cholanic acid-15 was obtained, which means, as indicated in the previous reports (1), (2), that the double bond is between C₁₄ and C₁₅.
2. To know the steric configuration of 3-hydroxyl group of α- and β-trihydroxyhomocholenes, they were hydrogenated to yield 3 (α), 7 (α), 12 (α)-trihydroxyhomocholane and 3 (α), 7 (?), 12 (?)-trihydroxy-homocholane respectively, which upon oxidation with bromine gave same 7-ketoderivative of m.p. 172°. Therefore three hydroxyl groups of α-trihydroxyhomocholene are all in α-configuration and, among these three hydroxyl groups of β-isomer, that of C₇ has β-configuration.
α-Trihydroxyhomocholene is 3 (α), 7 (α), 12 (α)-trihydroxyhomo-cholene and β-trihydroxyyhomocholene is 3 (α), 7 (β), 12 (α)-trihydroxy-homocholene.
The author is greatly indebted to President Dr. Toda for his encouragement and guidance, and to Dr. Shimizu, the President of Okayama University, for his permittance to use his laboratory at case. The author also thanks for the economical assistance of the Supporter's Association of our College.

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1. Inhibition of the over all reaction of two enzymes, acetylcholin-esterase and cholinesterase, by hydrogen ion and tetraethylammonium bromide was investigated from the kinetic point of view.
2. It is assumed that the inhibition at acid side is caused by hydrogen ion following the first order kinetics with response to hydrogen ion concentration.
3. This inhibition by hydrogen ion seems to be non competitive inhibition with substrate.
4. The inhibition by tetraethylammonium bromide is caused by the combination of one inhibitor molecule to one enzyme molecule.
5. pK_I of the reaction of tetraethylammonium bromide with acetylcholinesterase and cholinesterase was obtained at 3.91 and 3.88, respectively.
6. Based on the data obtained, the difference of the nature of the two enzymes are discussed. It is suggested that each of these two enzymes contain a single anionic site.

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Several strains of microorganisms, which grow well on the medium containing pyrrolidone carboxylic acid as a sole source of carbon and nitrogen, have been isolated from soil.
Using one of them, aerobic decomposition of pyrrolidone carboxylic acid was studied. As the decomposition products by washed cell suspension, glutamic acid, succinic acid, acetic acid and other organic compounds were detected.
The cell-free preparation, which can oxidize PGA completely, was obtained from this organism.
The first stage of the oxidation of PGA was concluded to be neither hydrolysis to GA nor decarboxylation to pyrrolidone.
A possible pathway (via pyroglutaramic acid) was discussed.
The authors wish to express their sincere thanks to Prof. S. Akabori, Prof. S. Funahashi and Dr. B. Maruo for their kind guidance and many useful suggestions throughout the present work.

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1. The oxidation of lactate by C. diphtheriae cultivated in an irondeficient medium was not inhibited by cyanide, azide and pyruvate, while that in an iron-sufficient medium was inhibited by these inhibitors. By Ag and Cu ions, both were inhibited seriously. In the oxidation product of the former case, acetate was found, while in that of the latter, pyruvate was demonstrated.
2. The oxidation of lactate by the cell-free extract of C. diphtheriae cultivated in an iron-deficient medium were accelerated by the addition of FAD, and not by FMN, free riboflavin, DPN, cytochrome c and Mg ion. The oxygen uptake were inhibited by Cu and Ag ions, but not by cyanide, azide or hydroxylamine.
From these facts, it will be considered that the lactic oxidase formed by C. diphtheriae adaptively to the irondeficient condition was an auto-xidizable flavin enzyme which catalyzes the reaction from lactate to acetate.

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1. The effect of folic acid and SH-glutathione on histidine de-aminase of the rabbit, which was reported in the previous papers, was reconfirmed (1). In this report Co^_??_ was found to be another essential supplement.
2. When EDTA was added in the process of enzyme purification, the activity of the purified enzyme was no longer restored by Co^_??_, Mn^_??_, Zn^_??_ or Cd^_??_, but with addition of folic acid, SH-glutathione and Co^_??_, the inactive enzyme regained its activity. The activation of Mn^_??_, Zn^_??_ and Cd^_??_ was discussed.
3. From one molecule histidine, one molecule ammonia was produced by the thus activated enzyme and as the metabolite urocanic acid was proved by means of paperchromatography.
4. Folinic acid was found not to have such a restoring effect on histidine deaminase.
5. The disaccordance between Kato et al. (12) and the authors was discussed and it became clear, that this was to be attributed to the difference of the experimental animals.

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The structure of lysozyme monolayers was investigated by the measurements of surface pressure, surface viscosity and surface potential. Following four distinct results were obtained.
(1) The reproducibility of the surface potential-area curve of lysozyme was very high at larger areas. The region in which film potentials fluctuate violently appeared as the film was compressed. Further compression beyond the area from which the surface viscosities began to rise steeply made the reproducibilities of the potentials very high. These facts are related to the aggregation state of lysozyme molecules. Therefore, the change in the state of lysozyme monolayer at its isoelectric point might be inferred from the curve of mean deviations of the observed ΔV values plotted against areas.
(2) The curves of surface potentials plotted against pressures were represented by a single curve and did not depend on the spreading solutions. The assumptions for the structure of lysozyme monolayers described in Part II were substantiated from this fact.
(3) The presence of sodium sulfite affects the F-A, η-A and ΔV-A curves of lysozyme monolayer. The reduction of intermolecular disulfide bonds were shown from various observations. When lysozyme was reduced with sulfite in spreading solution, the monolayers spread from it had very high viscosities from larger areas. The formation of strong intermolecular crosslinks including disulfide was suggested in this case.
(4) The presence of sodium sulfite in the substrate had no effect on the viscosities of ovalbumin monolayers. In this case the monolayers were spread from a solution of ovalbumin in 8M urea. Never-theless, the evidence of the formation of inter- or intra-molecular disulfide bonds was not obtained.
The author wishes to express his sincere thanks to Prof. T. Isemura for his kind guidance throughout the present work and to Prof. S. Akabori, Mr. K. Ohno and Mr. I. Ha runa in the Faculty of Science of Osaka University who supplied the valuable samples of lysozyme and ovalbumin.

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1. The shape of caprylic acid or once boiled sesame oil in a saline solution is spherical. When egg white is added, the shape is transformed from sphere to disk and at the same time the creases appear on the surface of droplets.
2. Under suitable conditions of the dispersion medium with regard to NaCl concentration and pH, it turns out to be biconcave discoid. In the case of caprylic acid such salt concentration exists in the range of 0.05-0.4M and pH of 5.6-6.2, and in the case of sesame oil the salt concentration in the range of 0.1-0.3M and pH at 8.2-9.4.
3. These phenomena are related to the coagulation of protein on the oil-water interfaces.
We wish to thank heartly to Dr. Keizo Kodama, President of Tokushima University, for his kind revision.

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Aerobic oxidation of triose reductone is catalyzed by the crystalline turnip peroxidase. The reaction is composed of the two successive reactions similarly as reported by Chance with aerobic oxidation of dihydroxymaleic acid by the horse-radish peroxidase.
The presence of a trace amount of H₂O₂ is indispensable to the first oxidative reaction and Mn^_??_ does not play any essential role in this reaction.
Other heavy metals such as Cu^_??_ and Hg^_??_ have a very interesting effect on the reaction.
Our thanks are due to Prof. Takasugi for generous advices.

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1. The nitro-reducing capacity of the mammalia in vitro was discussed.
2. The liver, kidneys, heart, muscle, lung, testicles, spleen, uterus, vagina, and ovary of rats were homogenized and examined, and the former seven were found able to reduce p-nitrophenol in the above order.
3. The reduction of the nitro group by the liver is inhibited by cyanide, monoiodoacetic acid, sodium azide, and thiourea, suggesting the indispensable participation of heavy metals in the reduction mechanism.
4. Dialysis removed the reducing capacity of the liver, which is restored by the addition of a boiled juice of the liver, succinate, glucose plus DPN, and alcohol plus DPN.
5. Acetone precipitation also removed the capacity, which was restored by the addition of the boiled juice, glucose and alcohol with DPN.
6. The acetone fractionation of the liver homogenate affords a fraction which possesses nitro-reducing capacity only when coupled with alcohol dehydrogenase system (alcohol plus alcohol dehydrogenase plus DPN). The alcohol dehydrogenase system failed to reduce p-nitrophenol in the absence of the nitroreductase fraction of the liver.
7. The difference in the order of the distribution between the nitro-reducing capacity and succinic dehydrogenase activity was shown and the existence of an enzyme was discussed which plays an indispensable role directly in the reduction of the aromatic nitro group in the mammalia. This enzyme may be termed a “mammalian nitroreductase.”

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1. Both antipodes of glucose, galactose, mannose and arabinose were compared as to the absorption rate, glycogen formation in the liver, the blood sugar level and their elimination in the urine.
2. Both forms of these sugars examined were absorbed from the intestine increasing linearly for 80 minutes and no evidence has been obtained of any remarkable difference of the absorption rate between the both antipodes of each sugar.
3. The selective absorption of the unnatural enantiomorphs of hexose and pentose so far examined seemed to have some relation to the phosphorylation in the intestinal mucosa.
4. The unnatural form of sugars studied was not concerned with the formation of liver glycogen and likely to be eliminated in the urine without utilization.
The author wishes to express his deep gratitude to Prof. Dr. R. Hirohata, director of the Department, for the carefull guidance given him throughout the present research.
The present work has been partly aided by the Scientific Research Fund of Ministry of Education.

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