Yasuo Kakimoto

Isolation and identification of NG-Monomethyl NG, NG-Dimethyl- and NG,NG-Dimethylarginine from the hydrolysate of proteins of bovine brain

Abstract N G -Monomethylarginine was isolated from the hydrolysate of a protein fraction of bovine brain. Its identification was based on elementary analysis, alkaline hydrolysis, nuclear magnetic resonance, infrared spectrum, paper electrophoresis and chromatography. N G , N G - and N G , N G -dimethylarginine were also isolated from the same source and identified. Their concentrations were determined in the protein fractions of various organs and subcellular components of brain and liver of rats.

β-Aminoisobutyrate-α-ketoglutarate transaminase in relation to β-aminoisobutyric aciduria

Abstract β-Aminoisobutyrate-α-ketoglutarate transaminase described by Kupiecki and Coon was further purified from hog kidney. The enzyme catalyzed the transamination with its l isomer while the d isomer, the natural form, was practically inactive as the substrate. The activity of the enzyme in the kidney of an hereditary high excretor of β-aminoisobutyric acid was not different from the activities of the low excretors. These findings indicate that the enzyme is not the principle enzyme catalyzing the degradation of the amino acid in vivo, and suggest the occurrence of another enzyme reaction by which d -β-aminoisobutyric acid is metabolized.

Isolation of γ-l-glutamyl-l-glutamic acid and γ-l-glutamyl-l-glutamine from bovine brain

Abstract Two peptides have been isolated from 28.5 kg of bovine brains using a combination of ion-exchange chromatographic separations. They were identified as γ- l -glutamyl- l -glutamic acid and γ- l -glutamyl- l -glutamine. The synthesis of these peptides has been described.

METHYLATED AMINO ACID RESIDUES OF PROTEINS OF BRAIN AND OTHER ORGANS

—Methods for the determination of methyl‐lysine, methyllarginine and methylhistidine residues of tissue proteins are described. They consist of preliminary purification of basic amino acids, enzymic removal of lysine, arginine and histidine followed by amino acid analysis. Recovery rates and specificities of the method were satisfactory. The contents of methylamino acids in proteins of mammalian organs were determined.

Identification of γ-glutamylserine, γ-glutamylalanine, γ-glutamylvaline and S-methylglutathione of bovine brain

Abstract Three γ-glutamyl dipeptides and a γ-glutamyl tripeptide were purified from bovine brain by a combination of ion-exchange chromatogaphic techniques. These were identified as γ-glutamylserine, γ-glutamylalanine, γ-glutamylvaline and S -methylglutathione by acid hydrolysis, terminal amino acid determination and comparison of paper chromatographic and paper electrophoretic properties of the isolated compounds with those of synthetized peptides.

Methylation of arginine and lysine residues of cerebral proteins

Abstract 1. 1. Incorporation of Me-14C S-adenosylmethionine into arginine and lysine residues of proteins was studied using extracts of rat brain and liver. The amino acids were methylated to form NG,NG- and NG,N′G-dimethyl- and NG-monomethyl-arginine and Ne-mono-, di- and trimethyllysine residues. The labelled products were identified using ion-exchange and paper chromatography, paper electrophoresis and chemical degradation. 2. 2. The methylation products of arginine residues have been tentatively identified as NG-methyl- and Nα,NG-dimethylarginines in other laboratories, but this is now proved to be incorrect. The compound proposed as NG-methylarginine is a mixture of NG,NG- and NG,N′G-dimethylarginines and that supposed to be Nα,NG-dimethylarginine is most likely NG-methylarginine.

Die Katechinamine im Zentralnervensystem

Das Forschungsgebiet fiber die chemischen ~bertrggersubstanzen des Nervensystems wurde hauptsiehlieh mit tier biologischen AnMyse der ans den Endignngen tier zentrifugalen Nervenfaser wie etwa der Endigung des Vagus, des Milznervs nsw., bei ]~eiznng freigese..tzten aktiven Stof{e entwickelt. Dei der Forschung der Ubertr/igerstoffe yon der zentripetMen Faser oder vom zentralen Nervensystem ist aber der direkte Nachweis der Substanzen praktiseh ausgesehtossen, da die freigesetzten Stoffe in den Synapsen im l~fiekenmark bzw. im Gehirn nicht direkt erfaBt werden kOnnen. Die Suehe nach Uber. trggerstoffen der Nervenleitungim zentralen Nervensystem wird dureh die Tatsache unterstfitzt, dab die [ ~ Substanzen in bestirnmten Fluorometrisehe ED-Methode Regionen des NervenMethoden systems in hoher Konzentration vorkommen, die Biosynthese und der Abbau der Substanzen dutch das Nervengewebe geleistet wer Flaoreszicrende den, und die Zunahme bzw. Substanzen die Abnahme des Gehattes an diesen Substanzen im Gehim bestimmte Funktions-~nderungen des Nervensystems hervorrufen. Als ~bertragerstoffe wurden bisher Aeetyleholin, Noradrenalin (NA), Adrenalin (AD), Serotonin (5-ItT), Histamin, Substanz P u. a. angenonlmen. Die Konzentration yon Histamin im zentralen Nervensystem ist abet so niedrig, dab die yon den irfiheren Autoren angegebenen Werte innerhalb der Fehlergrenze liegen. Die hohen Werte des ttistamingehaltes in den peripheren Fasern kamen aus dem hohen }Iistamingeha, lt der im Endoneurium und im Perineurium der peripheren Nerven existierenden Mastzellen. Die Annahme, dab Histamin mit der t~eiztibertragung tier peripheren Nervenfaser etwas zu tun h~be, seheint die experimentelle Unterstiitzung verloren zu haben. Dagegen wird die Bedentung von 5-HT und der Cateeholamine Ms mSgliehe Obertrigersubstanzen im zentrMen Nervensystem sehr lebhaft diskutiert. Im Jahre 1946 hat EuLs~ das Vorkommen yon NA im Organismus nachgewiesen und in demselben Jahre die Existenz auch im Gehirn des KMbs mittels biologiseher Nachweismethoden festgestelltL HOLTZ (1950) kam zu ihnlichen Ergebnissen ~. DamMs ist die MSgliehkeit in Betracht gezogen worden, dab NA nieht aus dem eigentlichen Himgewebe, sondern aus den beigemengten Nervenendigungen der sympathisehen Fasern peripheren Urspmngs an den Ge~aBw/~nden des Gehirns stamme. Vo~: (1954) hat die Verteilung yon NA im Hundegehima mittels der biologisehen Bestimmungsmethode untersucht und berichtet, dM3 NA besonders im Hypothalamus und im I:[irnsb~mm konzentriert verteilt seiK A~ bedeutender Beitrag auf diesem Gebiet wird die Entdeekung von 3-Hydroxytyramin (Dopamin, DA) im Gehirn

α-(γ-AMINOBUTYRYL)-LYSINE IN MAMMALIAN BRAIN: ITS IDENTIFICATION AND DISTRIBUTION

Abstract— α‐(γ‐Aminobutyryi)‐lysine was identified in rabbit brain. This compound was detected exclusively in the brain of mammals, but not in other tissues. It is not concentrated in any particular region of the rabbit brain.

Isolation and identification of γ-l-glutamylglycine from bovine brain

A peptide has been isolated from 28.5 kg of bovine brains through ion-exchange chromatography, and identified as γ-l-glutamylglycine. The identification was based on elementary analysis, determination of amino acid sequence, infrared spectrum, paper chromatography, paper electrophoresis and determination of configuration of glutamyl residue by l-glutamic acid decarboxylase (EC 4.1.1.15). The synthesis of α- and γ-l-glutamylglycine are also described.

OCCURRENCE AND FORMATION OF γ‐GLUTAMYLPUTRESCINE IN MAMMALIAN BRAIN

—An unknown radioactive compound was detected in the basic fraction of the trichloroacetic acid extract of rat brain injected with radioactive putrescine. This compound was purified from bovine brain and identified as γ‐glutamylputrescine by comparison of its behaviour with that of the synthesized glutamylamides. The amide seemed to be metabolized as rapidly as putrescine in rat brain.