Kinetics of Lys-bradykinin release by porcine pancreatic kallikrein from rabbit low molecular weight kininogen.

The initial rates of Lys-bradykinin release by porcine pancreatic kallikrein from rabbit low molecular weight kininogen are found to follow the Michaelis-Menten kinetics with kc = 0.62 sec-1 and Km = 1.93 microM at substrate concentrations 0.

Soluble guanylate cyclase of platelets: function and regulation in normal and pathological states.

Chromatography of 105,000 x g supernatants of human and rat platelets on DEAE-cellulose yielded identical elution profiles containing 2 protein fractions (peaks I and II). Only peak II was found to possess guanylate cyclase activity. In the spectrum of the 105,000 x g supernatant of human platelets the absorption maximum was specified at 410 nm (the Soret band) which disappeared from the spectrum of the active protein fraction (peak II) but was detected in the nonactive fraction (peak I).

Components of plasma and tissue kallikrein-kinin system in the urine of patients with latent, nephrotic and hypertonic forms of glomerulonephritis.

Activities of main components of KKS were estimated in the urine of patients with latent, nephrotic and hypertonic forms of chronic glomerulonephritis (ChGN) and compared to those parameters in urine of healthy persons. The data obtained allow to make a conclusion concerning the pathogenetic and the compensatory role of plasma KKS in the nephrotic form of ChGN.

Preparative isolation of polyphosphoinositides and other anionic phospholipids from natural sources using chromatography on adsorbents containing primary amino groups.

A new method for the preparative isolation of anionic phospholipids with the use of chromatography on adsorbents containing primary amino groups has been developed. The method combines elements of bioaffinity and ion-exchange chromatography. Synthesis of adsorbents based on Spheron and silica supports with immobilized neomycin, L-lysine, or aminoalkyl groups was carried out.

4-Trifluoromethylumbelliferyl glycosides as new substrates for revealing diseases connected with hereditary deficiency of lysosome glycosidases.

The following glycosides of 4-trifluoromethylumbelliferone: alpha-D-mannopyranoside, alpha-L-fucopyranoside, alpha-D-glucopyranoside, beta-D-glucopyranoside, alpha-D-galactopyranoside, beta-D-galactopyranoside, alpha-L-iduronide and beta-D-glucuronide were studied. 4-Trifluoromethylumbelliferyl glycosides were shown to be substrates for glycosidases. Some of them were cleaved even better than the corresponding methylumbelliferyl glycosides.

Increase in reactivity of human platelet guanylate cyclase during aggregation potentiates the disaggregating capacity of sodium nitroprusside.

1. Basal and stimulated guanylate cyclase activity during ADP-induced human platelet aggregation in comparison with the actions of sodium nitroprusside (SNP) on platelets was investigated. 2.

Nuclear topoisomerase I and DNase activities in rat diethylnitrosamine-induced hepatoma, in regenerating and fetal liver.

DNase activity in the presence of Ca2+ + Mg2+, Mg2+ alone, Mn2+ alone, or EDTA, and topoisomerase I activity were measured in nuclear extracts of diethylnitrosamine (DEN)-induced hepatomas, regenerating, fetal, and normal rat livers. In hepatoma tissue, the Ca/Mg-dependent DNase activity was lower than in normal tissue and nearly the same as in fetal liver. In the poorly differentiated hepatomas, Mn-dependent DNase activity was higher than in both moderately and well differentiated ones and than in normal liver tissue.

Activity of some proteinases and glycosidases in human leukemic lymphoid cells at various stages of differentiation.

Activities of some glycosidases and proteinases in human leukemic lymphoid cells at various stages of differentiation have been compared. It was found that cells with different immunological phenotypes gave different enzymic spectra. Glycosidases and proteinases in lymphoid cell precursors had higher activity level than the enzymes in mature T- and B- cells.

Role of heme in the regulation of human and rat platelet soluble guanylate cyclases.

The chromatography of soluble human and rat platelet guanylate cyclases (105000 g supernatants) on DEAE-cellulose in 50 mM Tris HCl buffer, containing 0.22 M NaCl, has yielded virtually identical elution profiles, each with two protein peaks (I and II). Only peak II was found to have guanylate cyclase activity.

Characterization of costal cartilage collagen in funnel chest.

Parallel measurements of pyridinoline content, the ratio of soluble:insoluble collagen, and the percentage of endogenous collagenolysis were made in samples of costal cartilage from forty-five children with funnel chest (FC) and from twenty-two control children. From an analysis of the influence of different factors, such as FC type (isolated or syndromic), a diagnosed syndrome, extent of FC depression (second or third), and age, two biochemical variants of FC-variants a and b, which were not related to the presence or absence of a known concurrent syndrome, were distinguished. These variants differed from each other in all the parameters under study.

Estimation and comparison of lysosomal and cytoplasmic pH of human fibroblasts from healthy donors and patients with lysosomal storage diseases.

Measurements were made of the pH of cytoplasm and lysosomes of cultured skin fibroblasts from healthy donors and from patients with lysosomal storage diseases (mannosidosis, Fabry's disease, and Krabbe's disease), and the effects of sucrose loading on normal fibroblasts were studied. The cytoplasmic pH of the pathological cells did not differ from control values, but the intralysosomal pH was significantly higher in sucrose-loaded normal fibroblasts and in cells from a patient with mannosidosis and from another with Fabry's disease. The change in pH observed accorded with an increase in size of the organelles, owing to accumulation of nonhydrolyzable compounds.

Diet-induced hypercholesterolaemia in the rabbit.

Intraspecies variation in diet-induced hypercholesterolaemia in rabbits, simulating atherosclerosis, was studied. The chinchilla rabbit population examined contained several subpopulations, as indicated by polymodal forms of histograms of plasma cholesterol levels. This finding indicates that the inclusion of subpopulations in an investigation can lead to erroneous conclusions, and that subpopulations should be identified before such work is undertaken.

Human smooth muscle VLA-1 integrin: purification, substrate specificity, localization in aorta, and expression during development.

A membrane glycoprotein complex was isolated and purified from human smooth muscle by detergent solubilization and affinity chromatography on collagen-Sepharose. The complex was identified as VLA-1 integrin and consisted of two subunits of 195 and 130 kD in SDS-PAGE. Liposomes containing the VLA-1 integrin adhered to surfaces coated with type I, II, III, and IV collagens, Clq subcomponent of the first component of the complement, and laminin.

Effect of carnosine on the activation of human platelet soluble guanylate cyclase by sodium nitroprusside and protoporphyrin IX.

Effect of carnosine on the activation of soluble guanylate cyclase by sodium nitroprusside and protoporphyrin IX was studied using human platelet 105000 g supernatants and partially purified heme-deficient guanylate cyclase preparations. In experiments with 105000 g supernatants, carnosine (1 mM) inhibited the enzyme activation by nitroprusside by about 70%. With the partially purified heme-deficient guanylate cyclase, the enzyme activation by nitroprusside was lowered by 86%, and the remaining insignificant stimulatory effect remained unchanged upon carnosine addition.

Enzymatic properties of active form of human apolipoprotein (a).

Lipoproteins (d = 1.05-1.12 g/ml) were obtained from pooled serum by density gradient ultracentrifugation and used as a source for isolation of apolipoprotein (a) (apo(a].

Guanylate cyclase in human platelets with different aggregability.

The activity of human platelet guanylate cyclase, and the activation of the enzyme by sodium nitroprusside were decreased in platelets with increased aggregability; these platelets were obtained from diabetes mellitus patients. Anomalies in guanylate cyclase activity and ADP-induced aggregation were more pronounced in platelets from subjects with type II than those with type I diabetes.

Relationship of the multiple forms of human alpha-D-galactosidase and alpha-D-fucosidase in the normal and in Fabry's disease.

Activities and multiple forms of alpha-D-galactosidase of human kidney and liver in the normal and in Fabry's disease were comparatively studied using alpha-D-galactoside and alpha-D-fucoside as substrates. By isoelectric focusing alpha-D-galactosidase was shown to exist in multiple forms, one of which possesses both alpha-D-galactosidase and alpha-D-fucosidase activity. In Fabry's disease, caused by a deficiency of alpha-D-galactosidase A, we found only one form of alpha-D-galactosidase, which corresponded to form B (alpha-N-acetylgalactosaminidase) and was also able to split alpha-D-fucoside.

Secretion and intracellular degradation of collagen in cultures of normal and SV-40-transformed human fibroblasts.

With a pulse-chase technique, secretion and intracellular degradation of collagen were investigated in human cultured normal and SV-40-transformed fibroblasts. Normal cells at a proliferative phase of growth secreted collagen more actively than the stationary phase (resting) cells. Transformed fibroblasts secreted protein at a lower rate than both normal cell types.

Inhibition of monoamine oxidase by esters and peptides of aromatic amino acids.

Methyl esters of aromatic a-amino acids, peptides with N-terminal tyrosine and C-terminal arginine, and amides of peptides with N-terminal aromatic amino acids all inhibit monoamine oxidases A and B from rat liver mitochondria with an IC50 of 0.2-3 mM.

Mitogenic effect of kallikrein from human urine on cultured human skin fibroblasts. Analysis of the combined action of kallikrein, insulin, and fibroblast growth factor on DNA and RNA synthesis.

Kallikrein isolated from human urine was capable of stimulating DNA and RNA synthesis in cultured human skin fibroblasts in media with a low serum content. The same concentration of kallikrein had a different effect on the DNA and RNA synthesis in different fibroblast lines, which was attributed to differences in the sensitivity of the cells to kallikrein. At a dose of 0.

Compensational dependence of activation parameters of membrane enzymes.

The activation parameters of reactions catalyzed by various membrane enzymes have been analyzed. In all cases there was compensational dependence between the enthalpy and the entropy of the reactions catalyzed. The differences found between lipid-activated, lipid-nonactivated, and water-soluble enzymes are discussed.