ATP- and antizyme-dependent endoproteolysis of ornithine decarboxylase to oligopeptides by the 26 S proteasome

Previously we reported that ornithine decarboxylase (ODC) is degraded ATP-dependently by the 26 S proteasome in the presence of antizyme (AZ), an ODC inhibitor (Murakami, Y., Matsufuji, S., Kameji, T., Hayashi, S., Igarashi, K., Tamura, T., Tanaka, K., and Ichihara, A. (1992) Nature 360, 597-599). Here we examined the cleavage of ODC by the 26 S proteasome. When ODC purified from ODC-overproducing cells was incubated with the 26 S proteasome and with AZ fused with maltose-binding protein (MBP) in the presence of ATP, ODC was degraded specifically without appreciable breakdown of MBP-AZ. The major degradation products of ODC, which were separated by high performance liquid chromatography on a reverse-phase column, were identified by N-terminal amino acid sequencing. The 26 S proteasome generated a variety of short peptides of 5-11 amino acid residues derived from regions throughout the ODC sequence. No detectable amounts of free amino acid residues were produced, indicating endoproteolytic degradation of ODC by the 26 S proteasome. Their major sites for cleavage of ODC by the 26 S proteasome were on the carboxyl sides of neutral/hydrophobic amino acid residues, but a few were on those of acidic or basic amino acid residues. These results demonstrate that the 26 S proteasome causes exhaustive endoproteolysis of the naturally occurring short-lived protein ODC in a multicatalytic and ATP-dependent manner.

[Outcome of coronary angioplasty and coronary artery bypass grafting in patients over 75 years old]

Mortality, morbidity, and 3-year survival rates were evaluated in patients aged over 75 years undergoing initial revascularization by percutaneous transluminal coronary angioplasty (PTCA) or coronary artery bypass grafting (CABG). The groups of 74 patients undergoing PTCA and 27 undergoing CABG had similar clinical characteristics including age, sex, emergency operation, prior myocardial infarction, and ejection fraction. The PTCA group contained significantly more patients with single vessel disease (44% vs 8%, p < 0.01) while the CABG group had more three-vessel or left main trunk disease (30% vs 70%, p < 0.01). The patients in the PTCA group demonstrated more prior cerebral vascular events, renal insufficiency, and abdominal aortic aneurysms. Angiographic revascularization was achieved in 112 of 130 lesions (86%) and in 63 of the 74 (84%) patients in the PTCA group. Hospital mortality for the PTCA group was 5.4% (two cardiac deaths and two non-cardiac deaths), but 0% for the CABG group. Myocardial infarction occurred in 1.3% and 3.7%, respectively (p = NS). Three-year survival, excluding hospital deaths, was 90% for patients with PTCA and 96% for those with CABG (p = NS). All these deaths were of non-cardiac origin. Both PTCA and CABG are safe and effective for selected patients over the age of 75 years.

[Fat distribution in Japanese women. Part 2. Fat thickness of extremities and classification of fat distribution of whole body]

The first object of this paper was to follow the previous paper in clarifying the characteristics of the fat distribution on the extremities. The subcutaneous fat thickness was measured at 64 points on the upper extremity and on 129 points on the lower extremity. The difference of the fat distribution between obese subjects and lean subjects was mainly observed on the back of the upper arm and the thigh. The second object of this paper was to clarify the characteristics of the fat distribution on both the trunk and the extremities and to study the factors which contribute to the fat distribution of the whole body. Average subcutaneous fat thickness over the body was 7.8 mm, and the standard deviation was 1.2 mm. Types of fat distribution of the whole body were classified by principal component analysis of average fat thickness in the 8 regions. The first component was the size factor which expressed the amount of fat on the whole body. The second component showed the contrast of fat distribution in the lower extremities and in the breast, abdomen, back and arms. These two components accounted for 90.79% of the variance of fat distribution. Measuring points, which showed high correlation coefficient with the average fat thickness of the whole body, were abdomen, subscapular, back, thigh and side breast.

Tyrosine derivatization and preparative purification of the sialyl and asialy-N-linked oligosaccharides from porcine fibrinogen

The N-linked oligosaccharides from porcine fibrinogen were purified following their release from glycopeptides using N-glycosidase F. In separate experiments, both sialyl and asialyl oligosaccharides were prepared from 5 g of fibrinogen. The reducing oligosaccharides were reacted with ammonium bicarbonate to form/oligosaccharide-glycosylamines and then derivatized with tert-butoxycarbonyl-L-tyrosine N-hydroxysuccinimidyl ester. Tyrosinamide--oligosaccharides were purified first by gel filtration chromatography and then by reverse-phase HPLC and the products were characterized by proton NMR and fast atom bombardment-MS. Porcine fibrinogen was found to have predominantly a single asialyl biantennary oligosaccharide containing a fucose linked alpha 1-6 to GlcNAc 1. The oligosaccharide possesses two sialylation patterns with a major form (70%) having a single N-acetyl neuraminic acid (NeuAc) residue linked alpha 2-6 to galactose on only one antenna and a minor form (30%) possessing two NeuAc residues linked alpha 2-6 to both terminal galactose residues. In addition to developing an isolation procedure and establishing the structures of porcine fibrinogen oligosaccharides, this study improves on the tyrosine derivatization technique as a general approach to isolate structurally diverse N-linked oligosaccharides from glycoproteins.

Effects of du-zhong leaf extract on serum and hepatic lipids in rats fed a high-fat diet

We evaluated the effects of Du-Zhong leaf extract on the serum and liver lipids in rats fed a high-fat diet supplemented with animal fat, cholesterol and cholate. The Du-Zhong leaf extract suppressed significantly the high-fat diet-induced increases in total serum cholesterol, serum triacylglycerol and hepatic triacylglycerol but not the total hepatic cholesterol. The Du-Zhong leaf extract also suppressed the high-fat diet induced increases in very-low density lipoprotein and low density lipoprotein without affecting high density lipoprotein cholesterol. These results suggest that Du-Zhong leaf extract may be beneficial for the regulation of hyperlipidemia.

Transfer of Propionibacterium innocuum Pitcher and Collins 1991 to Propioniferax gen. nov. as Propioniferax innocua comb. nov

16S ribosomal DNA analysis indicates that Propionibacterium innocuum is a phylogenetic neighbor of Luteococcus japonicus and that this pair of organisms branches intermediately between the genus Propionibacterium on the one side and the genera Aeromicrobium and Nocardioides on the other side. Phenotypically, strains of P. innocuum differ from species of Propionibacterium by exhibiting aerobic growth and possessing arabinose in the cell wall, they differ from species of Aeromicrobium and Nocardioides by the formation of propionic acid, and they differ from species of Luteococcus in morphology. Consequently, P. innocuum should not be classified with authentic Propionibacterium species, and the transfer of P. innocuum Pitcher and Collins 1991 to a new genus, Propioniferax, as Propioniferax innocua gen. nov., comb. nov. is proposed.

In vivo targeting function of N-linked oligosaccharides with terminating galactose and N-acetylgalactosamine residues

N-Linked biantennary, triantennary, and core fucosylated biantennary oligosaccharides were isolated from animal glycoproteins and derivatized at their reducing end with Boc-tyrosine. The terminal Gal residues were enzymatically removed and replaced with GalNAc. Tyrosinamide-oligosaccharides were radioiodinated and administered intravenously to mice. Pharmacokinetic and biodistribution studies revealed structure-dependent differences in the steady-state volume of distribution, total body clearance rate, and targeting efficiency. Tyrosinamide-oligosaccharides were found to resist metabolism relative to a natural triantennary glycopeptide which was rapidly degraded in vivo. Triantennary oligosaccharides containing terminal Gal or Gal-NAc targeted the liver efficiently whereas biantennary oligosaccharides containing terminal Gal residues and differing only in their core fucosylation avoided recognition by the asialoglycoprotein receptor and were cleared unmetabolized by renal filtration. In contrast, biantennary oligosaccharides containing terminal Gal-NAc residues targeted the liver with much greater efficiency than Gal-terminated triantennary oligosaccharide. Core fucosylation reduced the metabolism rate of tyrosinamide-biantennary in the liver. The results establish the utility of tyrosinamide-oligosaccharides as probes to analyze the ligand specificity of mammalian lectins in vivo and demonstrate that a GalNAc-terminated biantennary is a potent ligand for the asialoglycoprotein receptor.

Lysozyme requires fluctuation of the active site for the manifestation of activity

Mutations around His15 which lie far away from the active site, stimulated glycol chitin activity of lysozyme at physiological temperature. Del-Arg14His15 lysozyme, a mutant lysozyme whose Arg14 and His15 were deleted together, and has the highest activity among these mutant lysozymes, had a similar binding ability to a trimer of N-acetyl-glucosamine, a substrate analogue, relative to native lysozyme. This suggests that the increased activity was due to an increased kcat in the catalysis reaction. The H-D exchange rate of the N-1 proton in the Trp63 which is located in the active site cleft, was enhanced in the Del-Arg14His15 lysozyme, while 2-D proton NMR analysis revealed no conformational change around Trp63. We conclude that some sort of fluctuation at the active site might be required for the manifestation of activity. This theory is supported by the finding that the Del-Arg14His15 lysozyme showed a shift in temperature dependency of activity to lower temperatures compared with that of native lysozyme.

Stimulation by peptide histidine methionine (PHM) of adrenocorticotropin secretion in patients with Cushing's disease: a comparison with the effect of vasoactive intestinal peptide (VIP) and a study on the effect of combined administration of corticotropin-releasing hormone with PHM or VIP

The effect of peptide histidine methionine (PHM) on ACTH and cortisol secretion was examined in 12 female patients with Cushing's disease and 8 normal women. For comparison, we examined in both groups the effects of vasoactive intestinal peptide (VIP), human (h) CRH plus PHM, and hCRH plus VIP. Each peptide was given as an i.v. bolus in a dose of 100 micrograms, and plasma levels of ACTH and cortisol were measured before and at intervals up to 120 min after the injection. In all normal subjects, hCRH induced significant rises in ACTH (> 50% above the basal) and cortisol (> 20% above the basal), but PHM and VIP were without effect. In this group, hormonal responses after hCRH plus PHM and hCRH plus VIP were statistically indistinguishable from those after hCRH alone. Of the patients with Cushing's disease, 9 (75%) were responsive to hCRH, 5 (42%) were to VIP, and 3 (25%) were to PHM, showing significant increases in both ACTH and cortisol. All the 3 PHM responders were also responsive to VIP, and all the 5 VIP responders were also responsive to hCRH. Interestingly, the responders to VIP and PHM had higher ACTH and cortisol responses to hCRH compared with the nonresponders. In addition, in the patients with Cushing's disease the coadministration of hCRH with PHM or VIP produced additive increases in both ACTH and cortisol. These results suggest that PHM may be another hypothalamic hormone capable of paradoxically stimulating ACTH secretion in at least some patients with Cushing's disease. Although the ACTH-releasing action of PHM appears less potent than those of hCRH and VIP, the possibility was suggested that a certain common mechanism may operate in inducing the ACTH response to these 3 peptides.

[A case of unusual shaped pulmonary arteriovenous fistula]

Autopsy findings of pulmonary arteriovenous fistula (PAVF) was initially described by Churton in 1897. Since then, several hundreds of cases have been reported in Europe and the United States. In Japan, there has recently been an increase in case reports of PAVF. PAVF seems to be no longer a rare disorder in Japan. Several morphological classifications of PAVF have been reported. One of these classifies PAVF into 1) solitary types 2) multiple types and 3) diffuse telangiectasia. Another, for example, classifies the disorder into the following 3 types: 1) multiple telangiectasia 2) pulmonary arterial aneurysm and 3) pulmonary artery-left atrial communications. Many other classifications have been proposed. In the solitary type (PA aneurysmal type), fistulas are located at the relatively large, central vessels. Here we report a case of PAVF which presented not as a solitary aneurysm but rather as a distended and tortuous anomalous vessel.

[Staggered intensive chemotherapy using arbekacin, fosfomycin and ceftazidime on polymicrobial infections involving MRSA]

Bacteriological and clinical studies were carried out on staggered intensive chemotherapy regimen for methicillin-resistant Staphylococcus aureus (MRSA) infections combined with Gram-negative opportunistic pathogens as polymicrobial infections. The regimen consisted of administering ceftazidime (CAZ) 30 minutes after infusion of arbekacin (ABK) and a bolus injection of fosfomycin (FOM). The combination of these drugs strongly inhibited the growth of MRSA and Pseudomonas aeruginosa. By this combination treatment, both of MRSA and P. aeruginosa in mixed culture became more susceptible to killing by macrophages. We evaluated the clinical efficacy and safety of combination of ABK, FOM and CAZ in the treatment of 15 patients with MRSA infections. The total efficacy rate was 80.0% and the bacterial eradication rate of MRSA was 60.0%. It is considered that staggered intensive chemotherapy with ABK, FOM and CAZ is useful for such polymicrobial infections involving MRSA.

Suicide inactivation of aromatase in human placenta and uterine leiomyoma by 5 alpha-dihydronorethindrone, a metabolite of norethindrone, and its effect on steroid-producing enzymes

Norethindrone (NET; 17 alpha-ethynyl-19-nortestosterone), a progestogen component of the contraceptive pill, irreversibly inhibits aromatase activity in human placental microsomes. However, it is known also to be aromatized in vitro and in vivo to produce a biologically very active estrogen called ethynylestradiol (EE2). It is therefore inappropriate to administer a high dose of NET to estrogen-dependent cancer patients for a prolonged time period. In this study, we focused on 5 alpha-dihydronorethindrone (5 alpha-DHNET), a metabolite of NET that is not aromatizable, and the inhibitory effects of 5 alpha-DHNET on human placental and uterine leiomyoma microsomal aromatase and other steroid synthetases. 5 alpha-Dihydronorethindrone showed weak affinity for both estrogen and progestogen receptors. It inhibited significantly human placental aromatase activity in a dose-dependent manner (Ki = 9.0 mumol/l; Kinact = 0.024/min), as well as that of uterine leiomyoma, but did not influence cholesterol side-chain cleavage or 17 alpha-hydroxylase, 21-hydroxylase or 11 beta-hydroxylase activities. These results suggest that 5 alpha-DHNET may be useful as an aromatase inhibitor, whose use in large doses is expected to reduce the size of estrogen-dependent tumors.

Synaptobrevin/vesicle-associated membrane protein (VAMP) of Aplysia californica: structure and proteolysis by tetanus toxin and botulinal neurotoxins type D and F

Synaptobrevin/vesicle-associated membrane protein (VAMP) and syntaxin are potential vesicle donor and target membrane receptors of a docking complex that requires N-ethylmaleimide-sensitive factor (NSF) and soluble NSF-attachment proteins as soluble factors for vesicle fusion with target membranes. Members of this docking complex are the target of clostridial neurotoxins that act as zinc-dependent proteases. Molecular cloning of the Aplysia californica synaptobrevin cDNA revealed a 180-residue polypeptide (M(r), 19,745) with a central transmembrane region and an atypically large C-terminal intravesicular domain. This polypeptide integrates into membranes at both the co- and posttranslational level, as shown by modification of an artificially introduced N-glycosylation site. The soluble and membrane-anchored forms of synaptobrevin are cleaved by the light chains of the botulinal toxins type D and F and by tetanus toxin involving the peptide bonds Lys49-Ile50, Gln48-Lys49, and Gln66-Phe67, respectively. The active center of teh tetanus toxin light chain was identified by site-specific mutagenesis. His233, His237, Glu234, and Glu270/271 are essential to this proteolytic activity. Modification of histidine residues resulted in loss of zinc binding, whereas a replacement of Glu234 only slightly reduced the zinc content.

Phase I clinical trial of irinotecan (CPT-11), 7-ethyl-10-[4-(1-piperidino)-1-piperidino]carbonyloxy-camptothecin, and cisplatin in combination with fixed dose of vindesine in advanced non-small cell lung cancer

Irinotecan hydrochloride (CPT-11), a semisynthetic derivative of camptothecin, has been demonstrated to be active against solid tumors such as non-small cell lung cancer and colorectal cancer. Two combination phase I trials were undertaken to determine the maximum tolerated dose of CPT-11 in combination with cisplatin and vindesine in patients with advanced non-small cell lung cancer. All 46 patients (age 32-73 years) entered into these trials had a good performance status (Eastern Cooperative Oncology Group score, 0-1) and had received no prior chemotherapy or radiotherapy. In the first trial, 14 stage IV and 2 stage IIIb patients were studied; in the second trial 30 patients with stage IV disease were accrued. In the first trial, CPT-11 was given as a 90-min i.v. infusion on days 1 and 8 in combination with a fixed dose of cisplatin (100 mg/m2, i.v., on day 1) and vindesine (3 mg/m2, i.v., on days 1 and 8), every 4 weeks. The starting dose of CPT-11 was 25 mg/m2, and the dose was increased in increments of 25 mg/m2. In the second trial, the doses of either CPT-11 (days 1 and 8) or cisplatin (day 1) were escalated with a fixed dose of vindesine (same dose as the first study) given in a 4-week cycle. The starting doses of CPT-11 and cisplatin were 20 and 60 mg/m2, respectively, and the dose of either CPT-11 or cisplatin was increased in increments of 20 mg/m2. At least 3 patients were entered at each dose level in both trials. Use of granulocyte colony-stimulating factor or granulocyte-macrophage colony-stimulating factor was not permitted in this trial. In the first trial, grade 4 granulocytopenia and grade > or = 3 diarrhea were dose limiting at 50 mg/m2 CPT-11, which represented the maximum tolerated dose. At the subsequent dose of CPT-11, 7 new patients were requited at the 50% reduced dose level of 37.5 mg/m2 on days 1 and 8. Nine patients were evaluated for response, and 4 of them achieved a partial response. In spite of a low dose of CPT-11 (25-37.5 mg/m2), the maximum concentration in plasma of CPT-11 (> 0.4 micrograms/ml) reached > 10-fold the in vitro concentration of CPT-11 required for 50% inhibition of growth. In the second trial, the dose-limiting toxicities were grade 4 granulocytopenia lasting for > or = 7 days and grade > or = 3 diarrhea.(ABSTRACT TRUNCATED AT 400 WORDS)

Five D:C-friedo-oleanane triterpenes from the seeds of Trichosanthes kirilowii Maxim. and their anti-inflammatory effects

Five triterpenes with a D:C-friedo-oleanane skeleton, D:C-friedo-oleana-7,9(11)-diene-3 beta,29-diol (3-epikarounidiol), 7-oxo-D:C-friedo-olean-8-en-3 beta-ol (7-oxoisomultiflorenol), 7-oxo-8 beta-D:C-friedo-olean-9(11)-ene-3 alpha,29-diol, D:C-friedo-olean-8-ene-3 alpha,29-diol (3-epibryonolol), and D:C-friedo-olean-8-ene-3 beta,29-diol (bryonolol), the first four of which are new naturally occurring compounds, were isolated from the seeds of Trichosanthes kirilowii Maxim. The structures were determined by spectral and chemical methods. 3-Epikarounidiol, 7-oxoisomultiflorenol, and 3-epibryonolol showed marked inhibitory activity against 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced ear inflammation in mice. The 50% inhibitory dose of these triterpenes for TPA-induced inflammation (1 microgram) was 0.2-0.6 mg/ear.

Mechanism of FK506-induced glucose intolerance in rats

To clarify the mechanism of glucose intolerance induced by FK506, a novel immunosuppressant, 5 or 10 mg/kg/day of FK506 was dosed orally to rats for 2 weeks, and 125I-insulin binding to the erythrocytes, plasma glucose and insulin levels, and pancreatic insulin content were examined. Insulin binding to the erythrocytes of rat dosed with FK506 was similar to that to erythrocytes of the placebo control; Scatchard analysis confirmed that FK506 did not cause damage to the insulin receptor of the erythrocytes. Contrarily, FK506 caused a clear decrease of pancreatic insulin content as well as a slight decrease of plasma insulin level. The results suggest that the glucose intolerance induced by FK506 is associated with a decrease of insulin secretion, but is not associated with impairment of the insulin receptor.

Melanosis Riehl-like facial pigmentation in a Japanese case of AIDS

An AIDS patient with the cardinal complaint of severe pigmentation on the face is reported. Hyperpigmentation is an unusual symptom of AIDS. This is a Japanese patient who presented melanosis Riehl-like discoloration. The importance of pigmented lesions in patients who have not been given any anti-HIV agents has not been emphasized in the literature.

Postmitotic osteoclast precursors are mononuclear cells which express macrophage-associated phenotypes

We previously demonstrated that osteoclast-like multinucleated cells were formed within 6 days in cocultures of mouse osteoblastic cells and spleen cells in response to 1 alpha,25-dihydroxyvitamin D3[1 alpha,25(OH)2D3] which was added together with hydroxyurea on Days 4-6 (final 2 days of the 6-day coculture period). Using this coculture system, chronological changes of macrophage-associated phenotypes such as nonspecific esterase (NSE) and antigens to Mac-1, Mac-2, and F4/80 were examined in postmitotic osteoclast precursors during differentiation into osteoclasts induced by 1 alpha,25(OH)2D3 (10 nM) added on Day 4. Osteoclast differentiation was assessed by examining expression of calcitonin receptors (CTRs) by autoradiography using 125I-labeled salmon CT. CTRs were first detected on small mononuclear cells within 12 hr after adding 1 alpha,25(OH)2D3. The number of CTR-positive mononuclear cells attained a maximum at 24 hr and decreased thereafter. CTR-positive multinucleated cells were first observed at 24 hr and reached a maximum population at 48 hr. All CTR-positive cells showed tartrate-resistant acid phosphatase activity (a marker enzyme of osteoclasts). Most of the CTR-positive mononuclear cells which appeared at 12 hr were positive for NSE and antigens to Mac-1 and Mac-2, but negative for F4/80 antigen. The proportion of CTR-positive cells expressing NSE and Mac-1 to total CTR-positive mononuclear cells decreased time dependently. Like authentic osteoclasts, CTR-positive multinucleated cells were negative for NSE and antigens to Mac-1 and F4/80, but positive for Mac-2. These results indicate that postmitotic osteoclast precursors are mononuclear phagocytes with macrophage-associated phenotypes, some of which disappear rapidly during their differentiation into osteoclasts.

Replacement of proteasome subunits X and Y by LMP7 and LMP2 induced by interferon-gamma for acquirement of the functional diversity responsible for antigen processing

Proteasomes catalyze the non-lysosomal, ATP-dependent selective breakdown of ubiquitinated proteins and are thought to be responsible for MHC class I-restricted antigen presentation. Recently, we reported that gamma interferon (IFN-gamma) induced not only marked synthesis of the MHC-encoded proteasome subunits LMP2 and LMP7, but also almost complete loss of two unidentified proteasome subunits tentatively designated as X and Y in various human cells. Here, we show that subunit X is a new proteasomal subunit highly homologous to LMP7, and that subunit Y is identical to the LMP2-related proteasomal subunit delta. Thus, IFN-gamma appears to induce subunit replacements of X and Y by LMP7 and LMP2, respectively, producing 'immuno-proteasomes' with the functional diversity responsible for processing of endogenous antigens.

Multimerization of the mouse TATA-binding protein (TBP) driven by its C-terminal conserved domain

The conformational states of the mouse TATA-binding protein (TBP) in solution were studied. A histidine tag and a factor Xa recognition site-carrying mouse TBP was expressed in E. coli, highly purified, and its fundamental functions as a TBP were demonstrated. We analyzed the molecular states of mouse TBP by gel filtration and glycerol gradient sedimentation, and found that TBP forms heterogeneous multimers in solution. Direct binding of TBP molecules to each other was proven by the far-Western procedure. Analyses using TBPs truncated at the N- and C-termini demonstrated that the functionally important C-terminal domain was responsible for homomultimer formation, and the N-terminal domain enhances multimerization. Furthermore, it was found that the TATA sequence dissociates homomultimers, and only monomeric TBP binds to the TATA-box. We suggest that TBP shares structural motifs in the C-terminal conserved domain for intermolecular interaction and TATA-binding.