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Proteolytic activites in cell extracts of Trypanosoma cruzi.

Cell extracts of culture forms of Trypanosoma cruzi are capable of hydrolysing substances belonging to 4 different groups of protease substrates: (a) substrates for trypsin-like enzymes: benzoyl-arginine-p-nitroanilide and benzoylarginine-naphtylamide; (b) substrates for aminopeptidases: leucyl, lysl and glutamyl-beta-naphtylamide; (c) a substrate fochymotrypsin-like enzymes: carbobenzoxy-L-tyrosine-p-nitorphenylester, and (d) a nonspecific substrate for a broad range of proteases: azocasein. Some physico-chemical characteristics of each enzymic reaction were studied. They were found to be distint enought to allow attributing each hydrolytic activity to a separate enzyme.

Aminopeptidases

Histoenzymological study on desquamative cervico-vaginal cells.

Dihydrofolate dehydrogenase activity was histochemically investigated comparatively to the activities of 6-phosphogluconate, glucose-6-phosphate, malate and lactate dehydrogenases, NADH-2-tetrazolium dehydrogenase, esterases, beta-glucuronidase and leucyl aminopeptidase in smears of desquamative cervico-vaginal cells of negative and positive Papanicolaou classes. Dihydrofolate dehydrogenase was found active in a greater percentage of cells and stronger in individual cells of cervical carcinoma than in normal, inflammatory or dysplastic cervix uteri. The other enzymes activities were less specifically increased in dyskaryotic cells.

Carcinoma, Squamous Cell

Experimental chronic obstructive lung disease. I. Bronchopulmonary changes induced in rabbits by prolonged exposure to formaldehyde.

The prolonged exposure to formaldehyde induces in the rabbit lung reactional and dystrophic changes involving the intrapulmonary bronchi, the bronchioli and the lung tissue. These changes are represented by bronchial cell hyperplasia with hypermucigenesis, extrusion of bronchial cells, bronchiolar hypermucigenesis, parcellary squamous metaplasia or necrobiosis of epithelia, thickening of bronchial and bronchiolar walls by subepithelial cell accumulations, destruction of musculo-elastic structures with stenosis or ectasia; the vascular reactions are hyperhaemic and proliferative with an obstructive and fibrous tendency; the parenchymal lesions are atelectasias, intralobular emphysema, and cellular thickening of alveolar walls and interlobular areas. The acid phosphatase, Tween-60-esterase, naphthol-AS-D-acetate-esterase, proline-oxidase and hydroxyproline-2-epimerase activities are increasing, while the leucyl-aminopeptidase and beta-glucuronidase ones are decreasing. The qualitative observations are completed and sustained by quanitative studies of mucous cell kinetics, of cell accumulations and differentiations.

Animals

[Aminopeptidases in the serum and urine of patients with hyperthyroidism].

In patients with hyperthyroidism the serum activities of the leucine aminopeptidase (LAP) and the alanine aminopeptidase (AAP) as well as the alanine aminopeptidase excretion in the urine were determined. A significantly increased activity of the leucine aminopeptidase in the serum and an increased excretion of alanine aminopeptidase in the urine were found. The AAP in the serum did not show a significant increase of activity. On account of the changes in the serum and in the urine before and during therapy a low-grade participation of the hepatobiliary and renal systems which are clinically not uppermost is to be assumed. Increased excretion of AAP and hyperthyroidism coincide nearly without exception in out patients. Correlation-statistical investigations make it probable to regard the increased excretion of AAP in the urine as an indirect parameter of the peripheral metabolism in hyperthyroidism.

Adult

[Aminopeptidase system of Aspergillus flavus].

The aminopeptidases system contained in a complex of exocellular peptidhydrolases synthetized by Asp. flavus was studied. Separation of the system into individual enzymes of the type of leucin aminopeptidase, aminotripeptidase and specific leucyl-glycyl-glycine-aminopeptidase by the methods of salt fractionation. DEAE-Sephadex A-50 and DEAE-cellulose chromatography. These enzymes are characterized by a different degree of purification as well as by the presence of the multiple forms, anion and cation ones. The multiple forms differ in solubility, specific activity, chromatographic properties, thermostability. The presence of individual triglycine-aminotripeptidase is shown in the system. The differences are found in the properties of the enzymes splitting leucinamide and leucyl-glycine. There may be two different leucine aminopeptidases. Studies in correlation during hydrolysis of leucinamide and leucyl-glycyl-glycine and comparison of the fractions properties displaying the activities showed that there are no reasons to ascribe these both reactions to the effect of the same enzyme.

Aminopeptidases

[Isolation of "pregnancy-zone" proteins using immuno absorbents and study of possible enzyme activities].

The purification of the pregnancy zone protein by means of immunoadsorbents is described. The pregnancy zone protein antibody was isolated from an absorbed rabbit antiserum and coupled with CNBr-activated sepharose. The pregnancy zone protein was isolated from pregnancy serum by the specific antibody cross-linked with sepharose. Contaminating serum proteins were eliminated by "inverse" immunoadsorption using antibodies against these proteins coupled with sepharose. An immunoelectrophoretically pure pregnancy zone protein was obtained. By means of a combination of immunoprecipitation and enzyme reaction in agar gel could be excluded that the pregnancy zone protein possesses activities of the following 11 enzymes: ceruloplasmin, leucine amino peptidase, alkaline phosphatase, carboxylic esterase, lactate dehydrogenase, malate dehydrogenase, glycerophosphate dehydrogenase, glucose-6-phosphat-dehydrogenase, cholinesterase, acetyl cholinesterase and oxytocinase.

Adsorption

Peptidases in germinating barley grain: properties, localization and possible functions.

Barley grain contains about 10% insoluble reserve proteins. When the grain germinates the reserve proteins are hydrolysed to amino acids and transported to the growing tissues of the seedling. In the resting grain most of the reserve proteins are 'packed' into the non-living storage tissue, the starchy endosperm. During germination the internal pH of the starchy endosperm is about 5, and it contains high activities of proteinases (secreted by the living aleurone cells) and carboxypeptidases, all with pH optima between 4 and 6. As a whole the starchy endosperm of a germinating grain resembles a giant secondary lysosome. Adjacent to the starchy endosperm is a specialized absorptive and processing tissue, the scutellum. This organ contains very high activities of the 'acid carboxypeptidases' and also two 'alkaline peptidase': a leucine aminopeptidase and a dipeptidase, both pH optima at 8 to 10. The high peptidase activities in the scutellum suggest that the hydrolysis products of the reserve proteins are absorbed from the starchy endosperm as a mixture of amino acids and small peptides, which are hydrolysed to amino acids in the scutellum before transport to the growing seedling tissues.

Aminopeptidases

Intramolecularly-quenched fluorescent peptides as fluorogenic substrates ofleucine aminopeptidase and inhibitors of clostridial aminopeptidase.

Fluorogenic oligopeptide derivatives of the type Lys(ABz)-ONBzl, where ABz iso-aminobenzoyl (anthraniloyl), X stands for Ala Phe, or Ala-Ala, and ONBzlis p-nitrobenzyloxy, were synthesized and shown to be hydrolyzed by leucine aminopeptidase. The hydrolysis is accompanied by an increase in fluorescence due to disruptionof the intramolecular quenching of the fluorescent anthraniloyl moiety by the nitrobenzyester group. The spectral characteristics of the compounds are not consistent withan energy transfer mechanism according to Förster, therefore the quenching isassumed to be caused by a direct encouter between the quenching and the fluorecentgroups. The change in fluorescence that accompanies the enzymic hydrolysis ofthe first peptide bound was used for quantitative measurement of the activity ofthe activity of leucine aminopeptidase and for the determination of some of itskinetic parameters. A bacterial aminopeptidase from Clostrdium histolyticumthat is very similar to leucine aminopeptidase in its substrate specificity inits substrate specificity did not hydrolyze the above peptidederivatives. Thehydrolysis of leucine p-nitroanilide by this enzyme was found to be inhibitedby the three peptides and the corresponding inhibition constants were determined.

Aminopeptidases

Histochemical studies on the submandibular ganglia of marmosets (Callithrix jacchus and Callithrix penecillata).

The histochemistry of the neural cells was studied in the submandibular ganglia of 5 Callithrix jacchus (3 males and 2 females) and 4 Callithrix penicillata (2 males and 2 females). These cells contain neutral mucopolysaccharides, nucleoproteins and lipidic materia, but are apparently devoid of glycogen. It is impossible to demonstrate in them any reactivity for UDPG-GT, phosphorylases, ATPase at pH 6.3, leucine aminopeptidase and alanyl aminopeptidas. The reaction for the other searched enzymes was as follows: weak (F-1,6-P Ald and cytochrome oxidase), weak to moderate (ADH, 6-P-GDH, ICDH, SDH, MDH, alpha-GPDH and beta-OHBDH), moderate (G-6-PDH, F-1,6-PA, LDH and GDH), moderate to strong (ATPase at pH 7.4, nonspecific esterase and acid phosphatase) and strong (G-6-PA, NADH2,-TR, NADPH2-TR, ATPase at pH 8.5 and 9.4 and alkaline phosphatase).

Adenosine Triphosphatases