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Biomedical subjects

H Sumi

Publications and source records attributed to H Sumi.

At least 91 records · Page 5Linked to original sources

Plasma fibrinolysis after intraduodenal administration of urokinase in rats.

Plasma fibrinolysis in rats rose above the level of physiological fluctuations in a curve with two peaks at 1 and 6 h, following intraduodenal administration of high-molecular-weight urokinase (HMW-UK; MW 53,000; 124,000 IU/mg protein). Activation of plasma fibrinolysis was also confirmed with insolubilized enzyme (glass-coupled UK), but lacked the first activity peak. Plasma fibrinolytic enzyme isolated by affinity chromatography revealed strong fibrinolytic (1,120 IU/dl), pyro-Glu-Gly-Arg-pNA amidolytic (3,200 nmol/dl) and Glu-plasminogen activating (24.5 IU/dl) activities. Using specific UK antibody, it appeared that the first peak originated from the administered UK, while the second one derived from endogenous plasminogen activator. Dose response of UK was not observed, and the maximal effect was at about 5,000 IU/kg body weight.

Animals↗

Further purification and characterization of acid-stable protease inhibitor from ascites of an ovarian carcinoma patient.

An acid-stable protease inhibitor (AS-PI) has been previously demonstrated in ascitic fluid from patients with ovarian carcinoma. In this study, the AS-PI was further purified using DEAE-cellulose and isoelectric focusing (IEF), and a partial characterization was undertaken. On DEAE-cellulose ion-exchange column chromatography, AS-PI activity was observed in both adsorbed and non-adsorbed fractions. The former represented the main AS-PI peak. By IEF, the respective pI values were 1.6 and 4.5. By gel filtration, the molecular weight of the main (adsorbed fraction) AS-PI was 78 000. This AS-PI strongly inhibited trypsin and to a lesser extent chymotrypsin, but exerted no inhibitory effect on plasmin. It slightly inhibited SH proteases such as papain and ficin. Immunologically, AS-PI was distinct from alpha 1-antitrypsin, alpha 1-antichymotrypsin, inter-alpha-trypsin inhibitor, antithrombin III, C1-inactivator, alpha 2-macroglobulin and alpha 2-plasmin inhibitor. The main AS-PI reacted with and was neutralized by antiurinary trypsin inhibitor serum, and on immunoelectrophoresis, had a mobility slightly cathodal to serum albumin.

Adult↗

Marked increase of plasma acid stable/soluble trypsin inhibitor in hemodialysis patients.

The activity of acid stable/soluble trypsin inhibitor (ASTI) was found to be considerably elevated in the plasma of hemodialysis patients (80.3 +/- 24.6 U/ml; 21-fold higher than normal). The increased ASTI was a very acidic compound (pI = 1.66) with a molecular weight (Mr) of 55000 by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). Immunological identity of the ASTI to urinary trypsin inhibitor was confirmed.

Adolescent↗

Interaction of fibrinolytic activity between the tracheobronchial secretion and circulating blood of rats.

In order to clarify the origin and release mechanism of plasminogen activator in the tracheobronchial secretion of rats, electrophoretic analysis of the secretion and studies on the effects of certain vasoactive drugs on the activator activity in the secretion were carried out. From the results of electrophoretic analysis of the tracheobronchial secretion in non-treated rats, protease inhibitor composed of glycoprotein was not contained in the secretion in contrast to the circulating blood, but a protein of low molecular weight like albumin in the circulating blood was contained in the secretion. Furthermore, after injection of noradrenalin, the blood pressure was temporarily elevated and the fibrinolytic activity of the euglobulin fraction in the circulatory blood was also increased. Subsequent to this elevation of fibrinolytic activity in the circulating blood, the fibrinolytic activity in the tracheobronchial secretion increased. Based on these results, it is suggested that the increase of fibrinolytic activity in the circulating blood was due to increased release of plasminogen activator from the vascular wall, and the increased fibrinolytic activity of the tracheobronchial secretion was caused by a consequent increased transudation of plasminogen activator from the circulating blood into the tracheobronchial lumen.

Animals↗

A thiol protease inhibitor released from cultured human malignant melanoma cells.

A thiol protease inhibitor (TPI) was found in culture media of human malignant melanoma cells (Bowes) at 1.5 to 2.3 units/day/flask (full sheet, 75 sq cm). This amount well exceeded that for cultured nonmalignant cells (human fetal lung fibroblasts). In the intracellular region of the melanoma cells, TPI activity was localized mainly in the cytosol fraction. The difference in specific activities between the intracellular and extracellular TPI and the TPI accumulation in the culture media indicated that cultured melanoma cells release TPI. Partial purification and characterization of the TPI by column chromatography using Sephadex G-150, papain-Sepharose, and Sephadex G-50, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed two distinct TPIs with molecular weights of 56,000 and 9,800 to 10,800. The latter (main) TPI had a high specificity for thiol proteases and was heat stable (60 degrees for 60 min), like previously reported normal human TPIs. The inhibitor, however, differed from normal human TPIs in that it had a lower molecular weight than any normal TPI, was unable to inhibit bromelain, and exhibited a mosaic pattern; namely, the low-molecular-weight TPI resembled liver-type TPI but the pH stability curve resembled serum-type TPI. The thiol protease, cathepsin B, was not detected in culture media of this human melanoma cell line.

Cell Line↗

Radioimmunological quantitation of urinary trypsin inhibitor.

Using monospecific antibody to human urinary trypsin inhibitor, we developed a highly specific and sensitive radioimmunoassay (RIA) for measuring human urinary trypsin inhibitor. No cross-reactivity of the antibody with protein standard serum, which contained albumin, alpha 1-antitrypsin, haptoglobin, alpha 2-macroglobulin, transferrin, IgG and IgA, was observed. The sensitivity of the system was 10 ng of trypsin inhibitor per assay tube, and 5-10 microliters of urine was sufficient to determine the concentration of trypsin inhibitor in urine. The amounts excreted in the urine of 10 healthy men and 10 healthy women were 4.83 +/- 2.46 (mean +/- SD) and 3.86 +/- 1.35 mg/day, respectively. The correlation between estimates by RIA and those by enzymic assay was r = 0.96 (p less than 0.005). The method proposed here can be used to determine the concentration of urinary trypsin inhibitor in a small amount of biological fluids and cells.

Adult↗

A functionally active heavy chain derived from human high molecular weight urokinase.

Human high molecular weight urokinase, a plasminogen activator, when minimally reduced with 0.01 M 2-mercaptoethanol for 10 h at pH 8.0 and 25 degrees C and then carboxymethylated with sodium iodoacetate, gave two chains, a functionally active heavy chain with about 80% of the original activity and a light chain. These two chains were found to be linked by a single interchain disulfide bond. The functionally active heavy chain can be isolated by an affinity chromatography method with [N alpha-(epsilon-aminocaproyl)-DL-homoarginine hexylester]-Sepharose. The light chain, which has no enzyme activity, is not adsorbed to the affinity matrix, whereas the active heavy chain was adsorbed and subsequently eluted. The active heavy chain was further purified by gel filtration on Sephadex G-100. This preparation was found to be homogeneous by both analytical and sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis. The molecular weight of the active heavy chain was determined to be 33,000 by Sephadex G-100 gel filtration and 31,000 by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis. Its specific activity, with L-pyroglutamyl-glycyl-L-arginine-p-nitroanilide, was determined to be 208,000 IU/mg of protein. Approximately 87% active sites were found by p-nitrophenyl-p'-guanidino-benzoate titration with a molar activity of 7.41 X 10(9) IU/mmol of active site. The active heavy chain when compared to low molecular weight urokinase has a similar molecular weight, specific activity, and amino acid composition. The NH2-terminal residue found in the active heavy chain was lysine which was the same as that found in low molecular weight urokinase, whereas the NH2-terminal residues found in high molecular weight urokinase were serine and lysine. Serine is the NH2-terminal residue of the light chain of high molecular weight urokinase. The steady state kinetic parameters of activation of human Glu-plasminogen by the active heavy chain were also similar to low molecular weight urokinase, as were the amidase parameters of these enzymes. The Michaelis constants of activation (Kplg) were 2.11 and 2.21 microM, respectively; the catalytic rate constants of activation (kplg) were 51.7 and 44.1 min-1, respectively, with second order rate constants, kplg/Kplg of 24.5 and 20.2 microM-1 min-1, respectively.

Amino Acids↗

Acid stable protease inhibitor in ascites of ovarian carcinoma.

In patients with ovarian tumors, a novel protease inhibitor which is very stable in acid (AS-PI, acid stable protease inhibitor) was identified in the ascites and tumor fluid as well as in the urine and plasma. The highest AS-PI activity was observed in the tumor fluid of ovarian carcinomas (10.7 +/- 2.3 U/ml), followed by the ascites of ovarian carcinomas (8.2 +/- 4.2 U/ml). There was a significant difference in activity of the tumor fluid and ascites between malignant and benign tumors (p less than 0.005, p less than 0.05, respectively). The same antigenicity of AS-PI fractionated from ascites of ovarian carcinomas to urinary trypsin inhibitor was identified by double immunodiffusion and neutralization techniques. It migrated in the serum albumin fraction on immunoelectrophoresis. By gel filtration, the AS-PI in the ascites of ovarian carcinomas showed a molecular weight of 70000-80000. Two active components with molecular weights of 61300 +/- 2100 and 73300 +/- 2500 were detected by SDS polyacrylamide gel electrophoresis.

Chromatography, Gel↗

Activation of plasma fibrinolysis after intrarectal administration of high molecular weight urokinase and its derivative.

Following intrarectal administration of high molecular weight urokinase (molecular weight 53,000; 124,000 IU/mg protein) and its functionally active heavy chain (molecular weight 31,000; 212,000 IU/mg protein) to mice, activation of plasma fibrinolysis was observed. The plasma levels of pyro-Glu-Gly-Arg-pNA amidolysis and euglobulin fibrinolytic activities reached a maximum (43.4 +/- 5.3 nmol/ml and 10.8 +/- 9.4 mm2/0.03 ml, respectively) at 1-2 h after the administration of 300 IU of either enzyme per mouse, and thereafter, both activities declined slowly. Urokinase absorption into the plasma was further confirmed from the immunoreactivity of plasma enzymes isolated by affinity chromatography to each anti-urokinase serum.

Animals↗

Multiple molecular forms of acid-stable plasmin inhibitor derived from human urinary trypsin inhibitor.

It was found that cyanogen bromide (BrCN) treatment of the highly purified human urinary trypsin inhibitors (H-UTI; specific activity 1,897 U/mg protein, and L-UTI; specific activity 1,850 U/mg protein) readily produced new plasmin inhibitors with almost no loss of UTI activity. Five multiple forms of chemically cleaved inhibitors (UTIB-I, UTIB-II, UTIB-III, UTIB-IV and UTIB-V) could be isolated from BrCN-treated L-UTI by isoelectric focusing and gel filtration. These inhibitors were very acid-stable and their isoelectric points (pI) were 4.5, 4.6, 4.9, 5.1 and 6.4, respectively. The molecular weights by SDS-polyacrylamide gel electrophoresis were almost the same at about 23,000 +/- 3,000. Although these inhibitors showed both anti-plasmin and anti-trypsin activities, much higher anti-plasmin/anti-trypsin activities were observed in the cleaved inhibitors than in the parent UTI. They competitively inhibited human plasmin with Ki values of 3.0-4.1 X 10(-8) mol/l (H-D-Val-Leu-Lys-pNA substrate).

Antifibrinolytic Agents↗

Purification and some properties of a plasma protein which reacts with an antiserum against urinary trypsin inhibitor-1.

A plasma protein which forms a precipitation line with antiserum against urinary trypsin inhibitor was purified by ammonium sulphate fractionation, anti-urinary trypsin inhibitor rabbit IgG antibody coupled sepharose immunoadsorbent column chromatography and polyacrylamide-gel disc electrophoresis. By these procedures, 0.14 mg of purified material was obtained from 20 ml of plasma. It was homogeneous as ascertained by sodium dodecyl sulphate polyacrylamide-gel disc electrophoresis and had an apparent molecular weight of 90,000. It was found that this inhibitor was immunologically distinct from inter-alpha-trypsin inhibitor.

Alpha-Globulins↗

Purification and partial characterization of two forms of urinary trypsin inhibitor.

Crude urinary trypsin inhibitor was obtained by DEAE-cellulose column chromatography from normal fresh urine. By the purification of the crude urinary inhibitor on successive chromatography methods using Sephacryl S-200, DEAE-cellulose, CM-Sepharose CL-6B and Sephadex G-100, we detected two forms of urinary trypsin inhibitor: form I and form II. The specific activity of form I increased approx. 4-fold with a recovery of 60%, as compared to that of crude urinary trypsin inhibitor. N-terminal amino acids of form I and form II were determined to be alanine and valine, respectively. Molecular weights of forms I and II were estimated to be 67000 and 28000 by gel filtration on Sephadex G-100 and to be 43000 and 19000 by SDS-polyacrylamide gel electrophoresis. S-carboxymethylated form I migrated as a single band corresponding to a molecular weight of 59000 in SDS-polyacrylamide gel electrophoresis. From the results of the determination of a single N-terminal amino acid of form I and a single band of S-carboxymethylated form I, it is indicated that it is composed of single polypeptide chain. And the present study suggests that form I is a native form of trypsin inhibitor in normal human urine and form II is a fragmented product from form I in the purification steps.

Amino Acids↗

Studies on the activation mechanism of fibrinolytic enzyme system in plasma by human pancreatic elastase.

In the present study, the activation mechanism of fibrinolytic enzyme system in plasma by human pancreatic elastase was investigated. It was confirmed that human pancreatic elastase not only converted the co-existing plasminogen to low molecular weight-plasminogen which could be easily activated by the activator, but also inhibited alpha 2-macroglobulin and alpha 2-plasmin inhibitor which are antiactivators or fast reacting antiplasmins, and consequently, induced the activation of the fibrinolytic enzyme system in plasma.

Chromatography, Affinity↗

Low molecular weight trypsin-plasmin inhibitors isolated from papain treated urinary trypsin inhibitor.

Papain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chrymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotryspin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10(-7) - 2.12 X 10(-6) M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors of plasmin was thought to be different from that to trypsin or chymotrypsin.

Amino Acids↗