Influence of anti-LDL receptor antibody on the transfer of cholesterol from LDL to isolated lymphocytes in normal subjects.
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Antibodies↗
Biomedical subjects
T Hibino
Publications and source records attributed to T Hibino.
Coexisting type III hyperlipoproteinemia and familial hypercholesterolemia: a case report.
A 39-year-old man presented with type III hyperlipoproteinemia in association with heterozygous familial hypercholesterolemia (FH). He had extensive tuberous xanthomas over the knees and elbows and xanthomas in the Achilles tendons. He also had palmar xanthomas. He exhibited severe hypercholesterolemia and hypertriglyceridemia. This patient was heterozygous for FH, as evidenced by low low-density lipoprotein (LDL) receptor function on lymphocytes, and had type III hyperlipoproteinemia, as determined by apolipoprotein (apo) E phenotype 2/2 in isoelectric focusing of the E isoproteins and the presence of a broad beta band on electrophoresis. Because therapy consisting of diet restrictions and lipid-lowering agents such as clinofibrate and niceritrol did not decrease serum total cholesterol ([TC] 15.26 mmol/L) and triglyceride ([TG] 10.79 mmol/L) levels effectively, the patient underwent plasmapheresis once every 2 weeks using a dextran sulfate-cellulose column. Repeated plasmapheresis markedly reduced serum TC and TG and induced complete regression of the palmar xanthoma after 6 months. The severity of tuberous xanthomas on the knees and elbows was reduced after 2.5 years. After plasmapheresis, TC decreased to 1.94 mmol/L from 10.40 mmol/L and TG decreased to 0.33 mmol/L from 7.90 mmol/L. Plasmapheresis performed with a dextran sulfate-cellulose column was highly effective in removing the lipoprotein-remnant particles in this patient, leading to generalized improvement in the lipoprotein profile.
Adult↗
Expression and characterization of Met92Gln mutant plastocyanin from Silene pratensis.
To investigate the role of the copper-ligand Met92 in the structural and functional properties of silene plastocyanin (PC), Met92 was replaced with Gln, which is the purposed fourth copper-ligand in another blue copper protein, stellacyanin. By use of the recently developed expression system [Hibino et al. (1994) J. Biochem. 116, 826-832], the Met92Gln mutant of intermediate precursor plastocyanin was successfully expressed in Escherichia coli and accumulated in the periplasmic space as a mature protein. In contrast to the wild type, most of the Met92Gln mutant PC accumulated as an apoprotein. After purification, mutant apoprotein could incorporate copper ions, although less efficiently than the wild-type apoprotein. The absorption peak of Met92Gln mutant PC was blue-shifted from 597 nm in the wild type to 591 nm. The rhombic type EPR spectrum was obtained for the mutant in place of the axial spectrum in the wild type. Compared with that of the wild-type PC, the oxidation-reduction potentials of the Met92Gln mutant PC were lower by about 35 mV over the whole pH range examined. These results indicate that the Met92Gln mutant exhibited "stellacyanin-like" spectroscopic properties. Interestingly, the electron-transfer activities of the mutant PC with the physiological electron donor (cytochrome f) and acceptor (Photosystem I) were similar to that of the wild-type PC. Since Met92 is conserved in all the plastocyanins whose primary structures are known, we propose that the primarily function of Met as a copper-ligand is in the uptake of copper ions during folding rather than in electron-transfer activities.
Base Sequence↗
Site-directed mutagenetic study on the role of negative patches on silene plastocyanin in the interactions with cytochrome f and photosystem I.
To investigate the role of two highly conserved negative patches, residues #42-45 and #59-61, on the surface of plant plastocyanin, six mutants were constructed by site-directed mutagenesis of the intermediate precursor gene from Silene pratensis. The mutants were designed systematically to incorporate positive charges into the negative patches, and the net charge on negative patches was modified from -4 to +1. Upon expression in Escherichia coli, the mutant proteins were correctly processed to the mature size and accumulated as holo-proteins. Absorption spectra, EPR, and redox potentials of the purified mutant proteins were almost indistinguishable from those of the wild-type. It was found that the electron transfer rate from cytochrome f to plastocyanin decreased exponentially as the net charge on the negative patch (#42-45) was increased, whereas the modification of the other negative patch (#59-61) had no effect. Ionic strength dependence studies indicated that the rate constants at infinite ionic strength did not change significantly among the wild-type and the six mutants, and the electrostatic attraction energies between plastocyanin and cytochrome f decreased when residues #42-45 were modified, whereas the modification of residues #59-61 had no effect. These results clearly indicated that only one (#42-45) of the two negative patches is involved in the transient complex formation with cytochrome f. Essentially similar results were observed for the electron transfer from plastocyanin to the photosystem I reaction center (P700), although in this case, slight participation of the negative patch (#59-61) is suggested.(ABSTRACT TRUNCATED AT 250 WORDS)
Amino Acid Sequence↗
Augmented lung adenocarcinoma cytotoxicity by the combination of a genetically modified anti-Lewis Y antibody and antibodies to complement regulatory proteins.
Complement-dependent cytotoxicity (CDC) mediated by a chimeric anti-Lewis Y monoclonal antibody (cH18A; human IgG1) was investigated in this study. Human lung adenocarcinoma cell lines (PC7, PC9, and PC14) were used as the target cells. PC7 and PC9 cells, expressed Lewis Y antigen and were lysed by cH18A as effectively as by the parent mouse anti-Lewis Y antibodies (mH18A) in a concentration-dependent manner. PC14 cells did not express Lewis Y antigen and were not lysed by either cH18A or mH18A. cH18A mediated CDC activity against PC7 and PC9 cells was enhanced by the combined use of monoclonal antibodies directed against CD46(MCP), CD55(DAF), and CD59. These molecules are complement-regulatory proteins which protect host cells from CDC. PC7 and PC9 cells, showed high levels of surface expression of these proteins, PC7 cells were more susceptible to cH18A-mediated CDC than PC9 cells. Use of multiple blocking antibodies to the complement-regulatory proteins produced more enhancement of cH18A-mediated CDC than a single antibody. Moreover, expression of CD55 and CD59 by PC7 and PC9 cells was decreased after treatment with PI-PLC, resulting in increased susceptibility to cH18A-mediated CDC. Although the reason is unknown, PC7 cells became more susceptible to CDC than PC9 cells after PI-PLC treatment even in the absence of cH18A. These data suggest that chimeric monoclonal antibodies can be used to induce CDC against lung adenocarcinoma, and that such CDC is potentiated by a variety of antibodies blocking compliment-regulatory proteins on the tumour cell surface.
Adenocarcinoma↗
[Effects of Onpi-to (TJ-8117) on mesangial injury induced by anti Thy-1 antibody].
We investigated the effect of Onpi-to (TJ-8117) on the mesangial injury induced by anti-Thy-1 antibody. TJ-8117 (400 mg/kg/day, p.o.) given from the 1st day (from the day of injection of the anti-thymocyte serum) or 4th day (after mesangial proliferation), markedly inhibited the mesangial proliferation and hypercellularity in glomeruli. TJ-8117 prevented the increase in the number of PCNA or ED-1 positive cells in glomeruli. These results suggest that TJ-8117 is effective against glomerular disease with mesangial injury.
Animals↗
[The effect of corneal epithelial cells on the collagen gel contraction by keratocytes].
To understand the mechanism of corneal stromal wound contraction, we investigated the effect of corneal epithelial cells on the collagen gel contraction by keratocytes. Subcultured rabbit keratocytes embedded in type I collagen gel were cultured. Rabbit corneal epithelial cells were also cultured and the cultured medium was collected and used as an epithelial cell conditioned medium (ECCM). The collagen gel contraction by keratocytes was estimated by measuring the diameter of the collagen disc once a day for 5 days. The diameter of the collagen gel decreased in proportion to the number of keratocytes in the presence of fetal calf serum (FCS), but it decreased in inverse proportion to the concentration of collagen. The collagen gel contraction by keratocytes was enhanced by the addition of ECCM in a dose dependent manner. This stimulatory activity was found in ECCM obtained from 3 to 7 day cultivation of corneal epithelial cells. These findings demonstrated that keratocytes contracted collagen gel in the presence of FCS. It also appeared that corneal epithelial cells secrete a factor or factors that stimulate the collagen gel contraction by keratocytes.
Animals↗
[A case of renal vein thrombosis and pulmonary embolism associated with diffuse membranous glomerulonephritis: the usefulness of low-molecular-weight heparin and urokinase therapy].
We report a case of renal vein thrombosis (RVT) and pulmonary embolism associated with diffuse membranous glomerulonephritis. A 44-year-old Japanese male was referred to the Nephrology Department with heavy proteinuria. Renal biopsy revealed diffuse membranous glomerulonephritis and we administered PSL 30mg/day and dipyridamole 300mg/day. Three weeks later, he was admitted with severe chest pain, dyspnea and massive proteinuria. RVT and pulmonary embolism were detected on CT scan and perfusion lung scan. After a few days of continuous intravenous unfractionated heparin (UFH) therapy, we used 72 U (anti-FXa)/kg of intravenous low-molecular-weight heparin (LMWH) every 12 hours for 10 days. He also received urokinase at the dose of 120,000 U/day for 4 weeks and long-term therapy with warfarin potassium at the dose of 3 mg/day. One month later, the thrombi in the pulmonary arteries and inferior vena cava disappeared on CT scan and perfusion lung scan. LMWHs have a longer biological half-life and a lower bleeding tendency than UFH for an equivalent antithrombotic effect. This case indicates that intermittent intravenous LMWH administration combined with urokinase is effective against RVT and pulmonary embolism without any side effect.
Adult↗
High-level expression of porcine muscle adenylate kinase in Escherichia coli: effects of the copy number of the gene and the translational initiation signals.
Porcine muscle adenylate kinase (ADK) was overproduced in Escherichia coli using the expression plasmid with double A-T-G codon at the translational starting site and the Shine-Dalgarno (SD) sequence 10 bp apart from the first A-T-G. We used the expression vectors pKK223-3 and pMK2. pMK2 is about 10-20 times larger in copy number than pK223-3. For both vectors, duplication of A-T-G was effective and the quantity of the expressed ADK from the double A-T-G plasmid was 2 approximately 4-fold more than that achieved when only one A-T-G was present. The amount of the produced ADK was maximum in the case of using pMK2 with double A-T-G. The overproduced ADK formed inclusion bodies in E. coli. It was solubilized in 6 M guanidine hydrochloride and refolded. Through two steps of column chromatography, ADK was purified. It has the same amino acid composition and grossly the same activity as that reported by Schirmer et al. (1970). Its amino acid sequence of the NH2-terminal region was identical with that deduced from the cDNA sequence including the NH2-terminal methionine.
Adenylate Kinase↗
A novel lipoxygenase from rice. Primary structure and specific expression upon incompatible infection with rice blast fungus.
A novel lipoxygenase cDNA (3,007 base pairs) was isolated from rice leaves (Oryza sativa cv. Aichiasahi) which had been infected with an incompatible race of the rice blast fungus, Magnaporthe grisea. A single copy of the gene is present in the rice genome and encodes a protein of 923 residues with a molecular weight of 102,714. This gene product shares the least amino acid sequence homology among plant lipoxygenases identified to date. A novel feature of this gene product is a putative transit peptide sequence at the amino terminus, suggesting the enzyme is localized in chloroplasts. An active lipoxygenase was expressed from the cDNA in Escherichia coli and characterized. The lipoxygenase introduces molecular oxygen exclusively into the C-13 position of linoleic and linolenic acids. The gene is expressed at high levels 15 h after inoculation with an incompatible race of M. grisea, at a low level after inoculation with a compatible race of the pathogen, and is not expressed in mock-infected leaves. Gene expression begins at the same time that the pathogen begins to penetrate into leaf tissue. This novel lipoxygenase gene expression is a part of the early response of the host to pathogenic attack.
Amino Acid Sequence↗
Cyclophosphamide treatment of female non-obese diabetic mice causes enhanced expression of inducible nitric oxide synthase and interferon-gamma, but not of interleukin-4.
In pancreatic lesions of non-obese diabetic (NOD) mice the expression of inducible nitric oxide synthase (iNOS) and of the cytokines interferon-gamma and interleukin-4 were studied. Strong iNOS expression as determined at the level of transcription, translation and of enzyme activity was associated with destructive insulitis as seen 8-10 days after cyclophosphamide treatment of 70- to 80-day-old female NOD mice. Immunohistochemistry showed iNOS associated with infiltrating macrophages but not in endocrine cells. The enhancement of iNOS after cyclophosphamide correlated with an increase of T-helper type 1 (Th1) associated interferon-gamma expression while T-helper type 2 (Th2) associated interleukin-4 was the dominant cytokine prior to cyclophosphamide and after diabetes onset. We conclude that insulitis in young NOD mice is carried by Th2 cells while cyclophosphamide enhanced insulitis is determined by Th1 cells. Macrophages show two different functional states in insulitis; strong iNOS expression in macrophages is associated with destructive insulitis.
Amino Acid Oxidoreductases↗
Human eccrine sweat contains tissue kallikrein and kininase II.
We attempted to determine the level of sweat kallikrein (kininogenase) and to purify and characterize it using sweat collected over a white petrolatum barrier. Thermally induced eccrine sweat obtained from 24 healthy subjects showed kallikrein activity of 24.4 ng kinins generated/1 mg of sweat protein when heated plasma was used as the substrate and 16.1 ng kinin when purified low molecular weight bovine kininogen was used as the substrate. Sweat was sequentially purified by Sephacryl S-200, diethyaminoethyl Sephacel, and fast flow liquid chromatography Mono Q chromatography. Sweat kallikrein had a M(r) of 40,000 and was inhibited by aprotinin but not by soybean trypsin inhibitor. The peptide generated by sweat kallikrein was identified as lys-bradykinin using reverse phase high-performance liquid chromatography and by its amino acid sequence. Anti-human urinary kallikrein immunoglobulin G neutralized the sweat kallikrein activity completely, indicating that the sweat kallikrein is the glandular type. Purified sweat and salivary kallikrein showed similar M(r) and responses to inhibitors and antibodies. Using immunohistochemistry, kallikrein activity was localized in luminal ductal cells and in the peripheral rim of secretory coil segments, presumably the outer membrane of the myoepithelium. We also observed kininase activity in sweat at M(r) 160,000, which was inhibited by ethylenediamine tetraacetic acid, captopril, and angiotensin converting enzyme inhibitor peptide, indicating that it is kininase II (or angiotensin converting enzyme). Sweat also contains abundant non-kallikrein hydrolases for S-2266 and S-2302. The demonstration of glandular kallikrein, its tissue localization, and the presence of kininase II in sweat provide the basis for future studies on the physiologic role of the kallikrein/kinin system in the eccrine sweat gland.
Angiotensin-Converting Enzyme Inhibitors↗
Purification and partial sequences of Aralia cordata cinnamyl alcohol dehydrogenase.
Cinnamyl alcohol dehydrogenase (CAD) (EC 1.1.1.195) from a dicot, Aralia cordata, was purified to homogeneity and its properties were characterized. The enzyme shows a preference for cinnamyl alcohols and cinnamyl aldehydes as substrates. The M(r) is estimated at 72,000. The enzyme is composed of two heterogeneous subunits of slightly different sizes, and it differs from the bean enzyme in the size of subunits. Partial amino acid sequencing of the purified enzyme was carried out both from the N-terminus and using selected peptides obtained by cyanogen bromide cleavage.
Alcohol Oxidoreductases↗
Changes in plasma free and sulfoconjugated catecholamines before and after acute physical exercise: experimental and clinical studies.
To elucidate whether sulfoconjugated catecholamines in plasma, especially dopamine, serve as a source of free catecholamines, we examined the change in afterload on the deconjugating activity of catecholamines in isolated Langendorff perfused rat hearts. Dopamine-sulfate was administered under ordinary or high-work-load conditions. Free dopamine in the effluent was increased by the high-work-load of the hearts, whereas conjugated dopamine showed an apparent decrease. These results indicate the possibility that deconjugation of sulfoconjugated catecholamines is accelerated by a high-work-load. To obtain further evidence in humans, we also examined the changes in the plasma levels of free and sulfoconjugated catecholamines in healthy volunteers before and after marathon running. Free dopamine increased 1.99-fold from the baseline value after exercise, whereas conjugated dopamine decreased by 12%. Similarly, the plasma levels of free noradrenaline and adrenaline increased after exercise to 2.45- and 1.51-fold their respective baseline values, while conjugated noradrenaline and adrenaline both decreased. These clinical results, as well as those of the experimental studies, suggest that the increase in plasma free catecholamines after exercise is due not only to increased release from the sympathoadrenal system but also to accelerated conversion from sulfoconjugated catecholamines in the plasma.
Adolescent↗
Effects of dietary protein restriction and oil type on the early progression of murine polycystic kidney disease.
A paucity of research data exists on the potential for early dietary modification to directly retard cystic growth and proliferation in polycystic kidney disease (PKD). We have therefore examined the relative effects of dietary protein levels and oil type on the progression of disease in a murine model of PKD. In the first study, weanling DBA/2FG-pcy (pcy) mice were fed either a normal (NP), 25%, or low (LP), 6%, casein diet with 10% of either sunflower seed oil (SO) (containing n-6 fatty acids), or fish oil (FO) (containing n-3 fatty acids), in a 2 x 2 design. At the end of the dietary treatment, kidney weight relative to body weight was higher in mice on the NP diets. In addition, kidney phospholipid to kidney weight (mumol/g) was lower in pcy mice on NP diets, indicating that the increased kidney size was largely due to increased cyst development. Replacement of dietary SO with FO resulted in alterations in renal phospholipid fatty acid compositions: 18:2 n-6, 20:4 n-6, and 22:5 n-6 were lower, and 20:5 n-3, 22:5 n-3, and 22:6 n-3 were higher in FO-fed animals. No effect of dietary lipid type on disease progression was noted, however. In a second study, morphometric analysis revealed an 11% lower percentage cyst area and a 46% lower total cyst area (mm2) in kidney sections derived from mice on LP diets compared to NP diets. These results indicate that early dietary protein restriction in PKD prior to clinical manifestation of symptoms of the disease may have a significant impact on the pathogenesis of PKD.
Animals↗
Characterization of genes that encode subunits of cucumber PS I complex by N-terminal sequencing.
N-terminal amino acid sequencing was carried out to characterize the genes of the cucumber PS I complex (PSI-100) that contains eight polypeptides and catalyzes the light-dependent transfer of electrons from plastocyanin to ferredoxin. The genes of all subunits except the 17.5 kDa polypeptide in PSI-100 have been identified. These are psaA/psaB (65/63 kDa), psaD (20 kDa), psaE (19.5 kDa), psaF (18.5 kDa), psaH (7.6 kDa), and psaC (5.8 kDa). The 17.5 kDa polypeptide is a new protein and is designated tentatively as the gene product of psaM. N-terminal amino-acid sequencing indicated the presence of two polypeptides in the 7.6 kDa band. One of these is the gene product of psaH and is essential for the activity of the PS I complex, and the other one is as yet unrecognized and largely depleted in the PSI-100 complex. Gene products of psaG, psaI, and psaK, which have been proposed as the components of PS I complex, are not involved in the PSI-100 complex, but are involved in the PS I complex (PSI-200), which contains 120 chlorophyll per reaction center chlorophyll (P700) and light-harvesting chlorophyll a/b protein complexes. Three polypeptides (26,23 and 22.5 kDa) are not involved in the PSI-100 and are assigned as the apo-protein of light-harvesting chlorophyll a/b protein complexes.
Amino Acid Sequence↗
Reconstitution of mature plastocyanin from precursor apo-plastocyanin expressed in Escherichia coli.
The precursor plastocyanin from Silene pratensis (white campion) has been expressed in Escherichia coli. The precursor protein was accumulated in insoluble aggregates and partially purified as an apo-protein. The purified precursor apo-plastocyanin was processed to the mature apo-plastocyanin by chloroplast extracts. N-terminal amino-acid sequencing indicated that the processed protein was identical to the N-terminal amino-acid residues of mature plastocyanin that was deduced from the nucleotide sequence. The copper could be incorporated into the apo-plastocyanin of mature size in vitro, but could not into the precursor apo-plastocyanin under the same conditions. Absorption spectra and reduction potential of the reconstituted mature plastocyanin were indistinguishable from those of the purified spinach plastocyanin. The electron transfer activities of the reconstituted plastocyanin with both the Photosystem I reaction center (P700) and cytochrome f were almost the same as those of the purified spinach plastocyanin.
Amino Acid Sequence↗
Role of serum albumin as a carrier of 99mTc-complex to tumor tissue.
To elucidate a factor required for tumor-imaging 99mTc-labeled radiopharmaceuticals, in vivo behaviors of 99mTc-L-cysteine (99mTc-Cys) and 99mTc-2-mercaptoethylamine (99mTc-ME) were compared with that of 99mTc-DL-homocysteine (99mTc-Hcy) which had been found to accumulate in several experimental tumors. When these three complexes were intravenously injected into mice bearing Ehrlich solid tumor, their tumor affinity was found to depend on their binding ability to serum albumin; 99mTc-Hcy, the albumin-binding ability of which was highest of the three, was the most tumor-tropic. When the albumin-bound complexes of these three were injected, their tumor distributions were enlarged. These results suggest the importance of serum albumin in serving as a carrier for the transport of 99mTc-Hcy-related compounds to tumor tissue.
Animals↗