Showing papers by "Kyoto University published in 1982"

Role of Frontier Orbitals in Chemical Reactions

Abstract: Since the 3rd century for more than a thousand years chemistry has been thought of as a complicated, hard-to-predict science. Efforts to improve even a part of its unpredictable character are said to have born fruit first of all in the success of the \" electronic theory \". This was founded mainly by organic chemists , such as Fry, Stieglitz, Lucas, Lapworth and Sidgwick, brought to a completed form by Robinson and Ingold, and developed later by many other chemists. 1 In the electronic theory, the mode of migration of electrons in molecules is noted and is considered under various judgements. For that purpose, a criterion is necessary with respect to the number of electrons which should originally exist in an atom or a bond in a molecule. Therefore, it can be said to be the concept by Lewis of the sharing of electrons that has given a firm basis to the electronic theory. 2 In the organic electronic theory, the chemical concepts such as acid and base, oxidation and reduction and so on, have been conveniently utilized from a long time ago. Furthermore, there are terms centring closer around the electron concept, such as electrophilicity and nucleophilicity, and electron donor and acceptor both being pairs of relative concepts. One may be aware that these concepts can be connected qualitatively to the scale of electron density or electric charge. In the electronic theory, the static and dynamic behaviours of molecules are explained by the electronic effects which are based on nothing but the distribution of electrons in a molecule. The mode of charge distribution in a molecule can be sketched to some extent by the use of the electronegativity concept of atoms through organic chemical experience. At the same time, it is given foundation, made quantitative , and supported by physical measurements of electron distribution and theoretical calculations based on quantum theory. The distribution of electrons or electric charge-with either use the result is unchanged-in a molecule is usually represented by the total numbers (generally not integer) of electrons in each atom and each bond, and it was a concept easily acceptable even to empirical chemists as having a tolerably realistic meaning. Therefore, chemists employed the electron density as a fundamental concept to explain or to comprehend various phenomena. In particular, for the purpose of promoting chemical investigations, researchers usually rely upon the analogy through experience, and the electron density …

Cloning and sequence analysis of cDNA for bovine adrenal preproenkephalin

Abstract: The nucleotide sequence of cloned cDNA for preproenkephalin from bovine adrenal medulla indicates that the precursor protein contains four copies of Met-enkephalin and one copy each of Leu-enkephalin, Met-enkephalin-Arg6 -Phe7 and Met-enkephalin-Arg6 -Gly7 -Leu8, a previously undetected opioid peptide. The enkephalin and extended enkephalin sequences are each bounded by paired basic amino acid residues. Preproenkephalin may represent a multi-hormone precursor, like the corticotropin-β-lipotropin precursor.

Cloning and sequence analysis of cDNA for porcine beta-neo-endorphin/dynorphin precursor

Abstract: The primary structure of a precursor protein that contains beta-neo-endorphin, dynorphin and a third leucine-enkephalin sequence with a carboxyl extension has been deduced from the nucleotide sequence of cloned DNA complementary to the porcine hypothalamic mRNA encoding it. The three peptides are each bounded by Lys-Arg. This precursor protein, like adrenal preproenkephalin and the corticotropin/beta-lipotropin precursor, comprises multiple repetitive units and a cysteine-containing amino-terminal sequence preceded by a signal peptide.

Primary structure of α -subunit precursor of Torpedo californica acetylcholine receptor deduced from cDNA sequence

Abstract: DNA sequences complementary to the Torpedo californica electroplax mRNA coding for the α-subunit precursor of the acetylcholine receptor were cloned. The nucleotide sequence of the cloned cDNA indicates that the precursor consists of 461 amino acids including a prepeptide of 24 amino acids. Possible sites for acetylcholine binding and antigenic determinants on the α-subunit molecule are discussed.

Antibodies to adult t‐cell leukemia‐virus‐associated antigen (atla) in sera from patients with atl and controls in japan: A nation‐wide sero‐epidemiologic study

Abstract: A nation-wide sero-epidemiologic survey of adult T-cell leukemia virus (ATLV), detected es anti-ATLA (ATLV-associated antigen), was made in Japan. Sera from adult donors in 15 different locations were screened for anti-ATLA. High incidences (6 to 37%) of antibody-positive donors were found in seven regions, one in northern Japan, and the others in southwestern regions. These areas are ATLV-endemic areas corresponding to ATL-endemic areas. Examination of sera from healthy donors aged 6 to 80 years in ATL-endemic areas showed an age-dependent increase of seropositive donors with a maximum of about 30% at 40 years of age. Anti-ATLA was found in all but two of 142 patients with ATL. Anti-ATLA-positive patients with ATL were mainly found in ATLV-endemic areas, and only a few in ATL-nonendemic areas. Six patients with cutaneous T-cell lymphoma in ATLV-nonendemic areas gave a negative reaction for anti-ATLA. The geometric mean titer of anti-ATLA of patients with ATL was higher than that of healthy donors.

Transformation of human leukocytes by cocultivation with an adult T cell leukemia virus producer cell line

Abstract: The transmission of adult T cell leukemia virus, a human retrovirus, into fresh leukocytes from normal humans was examined. One of three virus-carrying cell lines, tested after being subjected to lethal x-irradiation, consistently transformed leukocytes from adult peripheral blood and umbilical cord blood. All the transformed cell lines expressed adult T cell leukemia virus-associated antigen, but transformed lines originating from adult and umbilical cord blood exhibited T cell and non-T, non-B cell surface natures, respectively. Efforts to transform human leukocytes with cell-free virus were unsuccessful.

Isolation and structural organization of the human preproenkephalin gene

Abstract: The primary structure of porcine preproenkephalin B has been elucidated by cloning and sequencing cDNA: it contains neoendorphin, dynorphin and leumorphin (containing rimorphin as its amino-terminus). These opioid peptides, each having a leucine-enkephalin structure, act on the kappa-receptor. We have now cloned a human genomic DNA segment containing the preproenkephalin B gene. The structural organization of this gene resembles those of the genes encoding the other opioid peptide precursors, that is, preproenkephalin A and the corticotropin-beta-lipotropin precursor (ACTH-beta-LPH precursor). The primary structure of human preproenkephalin B has been deduced from the gene sequence. The amino acid sequence homology observed between preproenkephalin B and preproenkephalin A, together with the similarity between their gene organizations, suggests that the two genes have been generated from a common ancestor by gene duplication.

An extracellular poly(3-hydroxybutyrate) depolymerase from Alcaligenes faecalis

Abstract: A strain of Alcaligenes faecalis T1, which was isolated from activated sludge, excreted an extracellular poly(3-hydroxybutyrate) depolymerase as it grew in a medium containing poly(3-hydroxybutyrate) as the sole carbon source. The molecular weight of the enzyme, purified from the culture medium to electrophoretic homogeneity, was 48 000 as determined by Sephadex G-100 filtration, and 50 000 by polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate. The pH optimum for the enzyme reaction was 7.5. The purified enzyme depolymerized poly(3-hydroxybutyrate) purified from Zoogloea ramigera 1-16-M, but did not attack the bacterial native poly(3-hydroxybutyrate)-containing granules. Km values were 13.3 micrograms/ml (= 0.78 microM, based on an estimated average molecular weight of 17 000) for poly(3-hydroxybutyrate) and 5.4 mM for the trimeric ester of D(--)-3-hydroxybutyric acid. Analysis of hydrolytic products of poly(3-hydroxybutyrate), several oligomeric esters of D(--)-3-hydroxybutyric acid, and the methyl ester of the trimeric ester indicated that the enzyme hydrolyzed these substrates from the free hydroxyl terminus, releasing D(--)-3-hydroxybutyrate dimer units one at a time.

Biosynthesis of Storage Proteins in Developing Rice Seeds

Abstract: Sodium dodecyl sulfate-polyacrylamide gel electrophoretic analysis of the starchy endosperm protein of rice (Oryza sativa L. Japonica cv Koshihikari) during seed development confirmed that storage protein begins to accumulate about 5 days after flowering. Two polypeptide groups, 22 to 23 and 37 to 39 kilodaltons, the components of glutelin, the major storage protein in rice seed, appeared 5 days after flowering. A 26-kilodalton polypeptide, the globulin component, also appeared 5 days after flowering. Smaller polypeptides (10- to 16-kilodaltons) including prolamin components, appeared about 10 days after flowering. In contrast, the levels of the 76- and 57-kilodalton polypeptides were fairly constant throughout seed development. Transmission electron microscopy and fractionation by sucrose density gradient centrifugation of the starchy endosperms at various stages of development showed that protein body type II, the accumulation site of glutelin and globulin, was formed faster than protein body type I, the accumulation site of prolamin.The 57-kilodalton polypeptide but not the glutelin subunits was labeled in a 2-hour treatment with [(14)C]leucine given between 4 and 12 days after flowering to developing ears. In vivo pulse-chase labeling studies showed the 57-kilodalton polypeptide to be a precursor of the 22 to 23 and 37 to 39 kilodalton subunits. The 57-kilodalton polypeptide was salt-soluble, but the mature glutelin subunits were almost salt insoluble.In vitro protein synthesis also showed that the mRNAs directly coding the 22 to 23 and 37 to 39 kilodalton components were absent in developing seeds and that the 57-kilodalton polypeptide was the major product. Thus, it was concluded that the two subunits of rice glutelin are formed through post-translational cleavage of the 57-kilodalton polypeptide.

The virus of Japanese adult T-cell leukaemia is a member of the human T-cell leukaemia virus group

Abstract: Human T-cell leukaemia virus (HTLV) has been isolated from several cases of cutaneous T-cell lymphoma in the United States1,2. Subsequently, adult T-cell leukaemia virus (ATLV) was also isolated from several cases of adult T-cell leukaemia in Japan3–5. Since the latter disease has been shown to be correlated ≥90% with the presence of high titred natural antibodies6–8 to two structural proteins of HTLV [p24 (ref. 9) and p19 (ref. 10)], it was important to compare HTLV and ATLV. We report here that by serology of p24 and p19 and by nucleic acid homology, ATLV appears to be as closely related to the original isolate of HTLV as different isolates of HTLV (from various regions of the world) are related to each other. ATLV is therefore either identical or closely related to HTLV.

Transformation Groups for Soliton Equations —Euclidean Lie Algebras and Reduction of the KP Hierarchy—

Abstract: This is the last chapter of our series of papers [1], [3], [10], [11] on transformation groups for soliton equations. In [1] a link between the KdV (Korteweg de Vries) equation and the affine Lie algebra A[^ was found: the vertex operator that affords an explicit realization of the basic representation of A{ [2] acts infinitesimally on the i functions of the KdV hierarchy. It was shown also that this link between the KdV equation and A[ comes from a similar link between the KP (Kadomtsev-Petviashvili) equation and gl(oo); the restriction to the subalgebra A{^ in gl(oo) reduces the KP hierarchy to the KdV hierarchy.

Electroweak Theory. Framework of On-Shell Renormalization and Study of Higher Order Effects

Abstract: The electroweak theory (the Weinberg-Salam theory) is reviewed emphasizing its aspects of a renormalizable gauge field theory with spontaneous symmetry breaking. The on-shell renormalization procedure is developed where all the renormalization constants are fixed on the mass shell of gauge bosons, fermions and Higgs bosons. It is applied to the calculation of radiative corrections to leptonic processes ν_µe → ν_µe, ν_µe → ν_µe, ν_µe → µν_e and µ → e ν_e ν_µ. The experimental significance of the radiative corrections and the effect of the corrections to the values of physical masses of W^± and Z are discussed. The relation among different renormalization procedures is clarified.

Gravity Waves on the Free Surface of an Incompressible Perfect Fluid of Finite Depth

Abstract: We consider the nonstationary waves on the surface of an incompressible perfect fluid of finite depth above the almost horizontal bottom in the case of two dimensional irrotational motion. We assume that the density of mass is equal to one, the gravitational field to (0, — 1) and at the time f^O the fluid occupies the domain 0 ( t ) ^ { ( y l 9 y 2 ) \ y l e R l 9 -h + b(yl)^y2^fi(t9 y,)} where h is a positive constant. We denote by Fb the bottom y2= — /i + Kj'i) and by Fs the free surface y2 = rf(t, J'i)The motion of the fluid occupying at t = 0 the given domain Q is described by the velocity v = (vl9 v2)9 the pressure p of the fluid and rj satisfying the equations

An efficient algorithm for K shortest simple paths

Abstract: This article gives an efficient algorithm for obtaining K shortest simple paths between two specified nodes in an undirected graph G with non-negative edge lengths. Letting n be the number of nodes and m be the number of edges in G, its running time is O(Kc(n, m)) if the shortest paths from one node to all the other nodes are obtained in c(n, m) [≥O(m)] time, and the required space is O(Kn + m). This time bound is better than those realized by existing algorithms, the best of which, proposed by Yen, requires O(Kn3) time, since c(n, m) ≤min[O(n2), O(m log n)] is known.

Molecular cloning and nucleotide sequencing of the gene for E. coli cAMP receptor protein

Abstract: The crp gene of E. coli, which codes for cAMP receptor protein (CRP), has been cloned in the plasmid pBR322 on the basis of a genetic complementation. One of the recombinant plasmids, pHA1, was shown to direct the synthesis of CRP in a cell-free system. The location of the crp gene was determined by constructing subclones carrying various portions of pHA1. The nucleotide sequence of the crp gene has been determined. The coding region consists of 627 base pairs (bp), which specify a protein of 209 amino acids. The predicted amino acid sequence from the DNA sequence is consistent with the amino acid sequence partially known and the amino acid composition of CRP. After the coding region, there is a G-C rich inverted repeat sequence followed by a run of Ts, which could be a terminator of the crp gene. A possible promoter sequence was found about 180 bp upstream from the initiation codon and was shown to act as a promoter in vitro and in vivo. There are two dyad symmetry regions in a 167 bp leader sequence.

Avian sarcoma virus Y73 genome sequence and structural similarity of its transforming gene product to that of Rous sarcoma virus

Abstract: From the complete nucleotide sequence of the genome of the avian sarcoma virus Y73, we have predicted amino acid sequence of p90gag-yes, the product of the transforming gene. Contrary to previous evidence from molecular hybridization studies, p90gag-yes was found to have much homology with the transforming gene product p60src of Rous sarcoma virus, suggesting that the cellular counterparts of the two (c-yes and c-src) originated from a common prototype sequence.

Note on Isotope Effect in Hydrogen Bonded Crystals

Abstract: By making use of a simple model potential for hydrogen bond, empirical relation between oxygen-oxygen distance and oxygen-hydrogen distance found widely in various hydrogen bonded crystals is explained. It is pointed out that, between theoretical prediction and ob­ served empirical data, there exists a salient discrepancy which is to be resolved by considering quantum effect or tunneling motion of hydrogen atom. The tunneling effect is treated by a variational method on a one dimensional model of hydrogen bond. Possibility of isotope effect in hydrogen bond length is examined and some speculation is given on a new interpretation of the isotope effect in ferro or antiferroelectric phase transition temperatures in hydrogen bonded crystals. In many of the ferroelectrics or antiferroelectrics, the hydrogen bonds con­ necting two oxygen (or other electronegative) atoms play an important role in their characteristic dielectric behaviours. Particularly when the phase transi­ tion in these substances is caused by order-disorder arrangements of protons, often is observed a large isotope effect in the. transition temperature Te. This fact manifests itself in that the protons or deuterons in the bonds are crucial elements to trigger the phase transition. Table I is a list of the hydrogen bonded crystals in which ferro (or antiferro) electric phase transitions take place with large isotope effect in Te. As seen from this table, the typical one is KH2 P04 (abbreviated as KDP), where the ratio TeD /Te H is about 1.7. The feature com­ mon to these hydrogen bonded crystals is the descent of Te with hydrostatic pressure p and the remarkable difference of the slope dTe/dp between for the Table I. The transition temperature Tc and its isotope effect in some ferro and antiferroelectric

A New in Vitro Assay for Human Thyroid Stimulator Using Cultured Thyroid Cells: Effect of Sodium Chloride on Adenosine 3′,5′-Monophosphate Increase*

Abstract: A new sensitive in vitro assay for human thyroid stimulator (HTS) was developed using human thyroid adenoma cells in monolayer culture After being cultured for 2 days, the cells were incubated in 03 ml Hank's solution without 08% NaCl (medium 1) and with thyroid stimulator (bovine TSH or 3 mg patient serum immunoglobulin G) at 37 C for 2 h The cAMP generated in the cells and the medium during the incubation was measured by RIA The assay was sensitive enough to elicit a 17- to 79-fold increase in cAMP at a TSH concentration of 10 microU/ml HTS was detected in 33 (825%) of the 40 patients with untreated graves' disease using this assay system In Hank's solution (medium 2), however, HTS was detected in only 5 (238%) of the 21 patients with untreated GRaves' disease cAMP increment upon stimulation by either TSH or HTS in medium 1 was larger than that in medium 2, and the difference in the response to HTS using the two media was much greater than that in the response to TSH Therefore, all HTS-immunoglobulin G studies showed higher activity using medium 1 than using medium 2 when expressed as bovine TSH equivalent Analysis by the Lineweaver-Burk plot of dose-response curves of the effect of TSH and HTS stimulation on cAMP increment showed an increase in the Km upon the addition of NaCl to the medium A similar inhibitory effect of NaCl (150 mM) was also observed in the assay system of human thyroid adenylate cyclase stimulator using crude plasma membrane fractions In summary: 1) an assay for HTS measuring cAMP production in cultured thyroid adenoma cells was developed and the assay using low NaCL medium was found to be the most sensitive, and 2) the inhibitory effect of NaCl on the response to HTS was much greater than that on the response to TSH These data suggest different behaviors of these two stimulators at their receptor sites

Application of immobilized lipase to regio-specific interesterification of triglyceride in organic solvent

Abstract: Lipase from Rhizopus delemar was immobilized by entrapment with photo-crosslinkable resin prepolymers or urethane prepolymers or by binding to various types of porous silica beads. The immobilized lipase preparations thus obtained were examined for their activity in converting olive oil to an interesterified fat (cacao butter-like fat), whose oleic acid moieties at 1- and 3-positions were replaced with stearic acid moieties, in the reaction solvent n-hexane. Although all of the immobilized preparations exhibited some activity, lipase adsorbed on Celite and then entrapped with a hydrophobic photo-crosslinkable resin prepolymer showed the highest activity, about 75% of that of lipase simply adsorbed onto Celite. Entrapment markedly enhanced the operational stability of lipase.