Analyses of azopigments obtained from the delta fraction of bilirubin from mammalian plasma (mammalian biliprotein).

Azopigments were obtained from the delta fraction of bilirubin (mammalian biliprotein) in cholestatic sera of men, rats and guinea pigs by diazo reaction with diazotized p-iodoaniline and analysed by t.l.c. Delta bilirubin of men and rats generated both unconjugated and glucuronide-conjugated azodipyrroles, whereas that of guinea pigs, in which the predominant form of conjugated bilirubin in serum was bilirubin monoglucuronide, generated only unconjugated azodipyrrole. We further analysed the azopigments by reversed-phase h.p.l.c. to distinguish their endovinyl and exovinyl isomers. The results indicated (a) that covalent binding of bilirubin to protein occurs exclusively on the conjugated dipyrrolic (either endovinyl or exovinyl) half of the parent conjugated bilirubin, (b) that both bilirubin monoglucuronide and bilirubin diglucuronide generate delta bilirubin, the latter yielding a 'conjugated' form of delta bilirubin that preserves the glucuronic acid moiety on the dipyrrolic half not bound covalently to protein, and (c) that therefore at least four forms of delta bilirubin exist in jaundiced sera of men and rats.     

Immunohistochemical techniques for detection of dermatan sulfate proteoglycan in tissue sections

Dermatan sulfate proteoglycan chains were detected in tissue sections treated with chondroitin B-lyase (0.01 units/ml) in 20 mM Tris-HCl (pH 8.0) for 1 hr, followed by staining with antibody 9A2 specific for unsaturated uronic acid coupled to N-acetylgalactosamine-4 sulfate. In contrast, after treatment with chondroitin B-lyase, no positive staining was observed with antibodies 3B3 and 1B5 which react to the unsaturated uronic acid coupled to N-acetylgalactosamine 6-sulfate and unsaturated uronic acid coupled to N-acetylgalactosamine, respectively. The distribution of dermatan sulfate thus revealed was confirmed by comparison with that found by monoclonal antibody 6B6 which reacts with small proteoglycans carrying dermatan sulfate side chains. The localization of positive staining in fibrous connective tissues was almost identical with these two procedures.     

Two structural genes on different chromosomes are required for encoding the major subunit of human red cell glucose-6-phosphate dehydrogenase

Structural analysis revealed the existence of two types of subunits in human red cell glucose-6-phosphate dehydrogenase. The two subunits have the same COOH region consisting of 479 amino acid residues, but their NH2-terminal regions are different in size and sequence. The minor subunit can be fully encoded by the X-linked G6PD cDNA, but the NH2-terminal region of the major subunit cannot. The cDNA and the gene for the NH2-terminal region of the major subunit were cloned and characterized. Southern blot hybridization indicated that the gene for the NH2-terminal region is on chromosome 6, not on the X chromosome. Northern blot hybridization demonstrated an existence of two separate mRNA components, one for the COOH-terminal region and the other for the NH2-terminal region. Two separate structural genes, the X-linked and chromosome 6-linked genes, must be coresponsible for encoding the single chain subunit. Either cross-translation of two mRNAs, or transpeptidation, or some other mechanism must be involved in the synthesis of human red cell G6PD.     

Possible relationship between poly(ADP-ribose)synthetase and formation of antibody against acetylcholine receptors in patients with myasthenia gravis

We examined the relationship of the serum levels of antibody against acetylcholine receptors to the serum levels of 13 enzymes, including various hydrolytic enzymes, poly(ADP-ribose)synthetase (Poly(ADP-ribose)Syn), and sialyltransferase (NANA-trans), in patients with myasthenia gravis. The patients were divided into two groups, depending on the presence or absence of thymoma. In spite of the absence of significant difference in the absolute levels of individual enzymatic activities between the two groups, the network relationships of such enzymes were quite different between the two groups. Of the 13 enzymes examined, only Poly(ADP-ribose)Syn showed a weak but significant correlation with the level of the antibody in the patients without thymoma. A multivariate study more clearly suggested the relationship between the antibody formation and Poly(ADP-ribose)Syn in the patients without thymoma. Such observations were not found in the patients with thymoma.     

Isolation and partial characterization of a novel form of low molecular weight kininogen from guinea pig plasma

Two kinds of low molecular weight kininogen (termed LK1 and LK2) were isolated from pooled plasma of guinea pigs. When polyclonal antisera raised against the individual proteins were used, immunological cross-reactions were observed between LK1 and high molecular weight kininogen (HK), but not either between LK1 and LK2 or between LK2 and HK. After tissue injury, plasma level of LK1 doubled while those of LK2 and HK remained relatively unchanged.     

NADPH production from NADP+ with a glucose dehydrogenase system involving whole cells and immobilized cells of Gluconobacter suboxydans

Summary A convenient and efficient method of NADPH production from NADP⁺ has been established using a glucose dehydrogenase system involving whole cells and immobilized cells of Gluconobacter suboxydans IFO 3172. Using airdried cells of the bacterium, the optimum conditions for NADPH production were examined, including the cell and glucose concentrations, NADP⁺ concentration, pH, buffer and reaction temperature. Under suitable conditions, the conversion ratio and the amount of NADPH accumulated reached about 100% and 73 mg/ml of the reaction mixture, respectively, after 1-h reaction. Intact cells of the bacterium also showed high NADPH production even in the reaction mixture without a surfactant. The addition of Triton X-100 to the reaction mixture and freeze-thawing treatment of intact cells enhanced the production. The NADPH production method was further improved by using cells of the bacterium immobilized by entrapment in a -carrageenan gel lattice. The immobilized cells had almost the same enzymatic properties as the air-dried cells. The conditions for the continuous production of NADPH with an immobilized cell column were also investigated. NADPH was produced in a good yield (about 95%) with this continuous process.     

Binding sites of HeLa cell nuclear proteins on the upstream region of adenovirus type 5 E1A gene.

Twenty one binding sites of HeLa cell nuclear proteins were identified on the upstream region of adenovirus type 5 E1A gene using DNase I footprint assay. The proximal promoter region contained five binding sites that overlapped the cap site, TATA box, TATA-like sequence, CCAAT box, and -100 region relative to the E1A cap site(+1). The -190 region was a potential site for octamer-motif binding proteins, such as NFIII and OBP100. An upstream copy of the E1A enhancer element 1 was the site for a factor (E1A-F) with the binding specificity of XGGAYGT (X = A, C; Y = A, T). E1A-F factor also bound to three other sites, one of which coincided with the distal E1A enhancer element. The distal element also contained a potential site for ATF factor. The adenovirus minimal origin of DNA replication competed for DNA-protein complex formation on the CCAAT and TATA box region and the -190 region, suggesting that these regions interacted with a common or related factor.     

Changes in polyamine-oxidizing capacity of peroxisomes under various physiological conditions in rats

Rat liver peroxisomal polyamine oxidase activity was determined under various physiological conditions by using the peroxidase method with phenol and 4-aminoantipyrine. N1-Acetylpolyamines such as N1-acetylspermine and N1-acetylspermidine were better substrates than the free polyamines. The polyamine oxidase activity in rat peroxisomes increased significantly when cell proliferation was high. The activity began to appear in fetal liver at the 16th approximately 18th day of pregnancy and peaked in neonatal liver on the first day (approx. 1.7-times higher than in adult liver). In regenerating rat liver, only polyamine oxidase activity among the peroxisomal enzymes tested was increased considerably 12 h after partial hepatectomy (approx. 2.8-fold over the control liver). Finally, the enzyme activity was significantly increased by administration of clofibrate, a peroxisome proliferator, which also causes hepatomegaly. In all cases, the increase in polyamine oxidase activity was not more than 3-fold. Since the level of polyamine oxidase activity in the normal liver is more than adequate in relation to the level of the substrates, the slight but significant increase under conditions of cell proliferation may have a role in modulating levels of polyamines in the proliferating liver tissue.     

Physiological state control of fermentation processes

In this article a novel approach to the control of fermentation processes is introduced. A "physiological state control approach" has been developed using the concept of representing fermentation processes through the current physiological state of the cell culture. No conventional mathematical model is required for the synthesis of such a control system.The main idea is based on the fact that during batch, feed-batch, or even continuous cultivation the physiological characteristics of the cell population, jointly expressed by the term "physiological state", are not constant but rather variable, which is reflected in expected or unexpected changes in the behavior of the control plant, and which requires flexible alteration of the current control strategy. The proposed approach involves decomposition of the physiological state space into several subspaces called "physiological situations." In every physiological situation the cell population expresses stable characteristics, and therefore an invariant control strategy can be effectively applied. The on-line functions of the physiological state control system consist of the calculation of physiological state variables, determination of the current physiological situation as an element of a previously defined set of known physiological situations, switching of the relevant control strategy, and calculation of the control action. Attention is focused on the synthesis of the novel and nonstandard part of the control system - the algorithm for online recognition of the current physiological state. To this end an effective approach, based on artificial intelligence methods, particularly fuzzy sets theory and pattern recognition theory, was developed. Its practical realization is demonstrated using data from a continuous fermentation process for single cell protein production.     

Stability of immobilized maltotetraose-forming amylase from Pseudomonas stutzeri

The stability of immobilized maltotetraose (G(4))-forming amylase (1,4-alpha-D-glucan maltoteraohydrolase, EC 3.2.1.60) from Pseudomonas stutzeri was investigated in both batch and continous processes. The inactivation process of the immobilized enzyme seemed to obey first-order kinetics, and the immobilized enzyme became more stable when coexisting with 20-30 wt % substrate and calcium ions. From intensive studies on the operational stability in the continuous process, the apparent half-life of G(4) productivity in a constant-flow system was mainly affected by the reaction temperature, substrate concentration, and initial immobilized enzyme activity. A new factor, immobilized enzyme stability factor f(s), was proposed to evaluate the half-life of the immobilized enzyme system.