An enzyme-immobilization method for integration of biofunctions on a microchip using a water-soluble amphiphilic phospholipid polymer having a reacting group

A water-soluble phospholipid polymer having an active ester group in the side chain, poly[2-methacryloyloxyethyl phosphorylcholine (MPC)-co-n-butyl methacrylate (BMA)-co-p-nitrophenyloxycarbonyl polyethyleneglycol methacrylate (MEONP)(PMBN), was used for the immobilization of an enzyme on a plastic microchip. The MPC polymers with BMA units were adsorbed onto the poly(methyl methacrylate)(PMMA) microchip, and the active ester group in the MEONP unit reacted with the amino groups of the proteolytic enzyme, trypsin. Trypsin was immobilized on the sample reservoir, and catalyzed the hydrolysis of the fluorescently labeled ArgOEt to Arg. The consequent separation of product from the substrate, and their detection, were integrated on the microchip and this meant that all procedures from the enzymatic activity to product detection were completed in less than three minutes.     

Studies on the Painlevé equations

Summary In this series of papers, we study birational canonical transformations of the Painlevé system , that is, the Hamiltonian system associated with the Painlevé differential equations. We consider also -function related to and particular solutions of . The present article concerns the sixth Painlevé equation. By giving the explicit forms of the canonical transformations of associated with the affine transformations of the space of parameters of , we obtain the non-linear representation: GG_*, of the affine Weyl group of the exceptional root system of the type F₄ A canonical transformation of G_* can extend to the correspondence of the -functions related to . We show the certain sequence of -functions satisfies the equation of the Toda lattice. Solutions of , which can be written by the use of the hypergeometric functions, are studied in details.     

Copolymerization of carbon disulfide and N-(β-cyanoethyl)ethylenimine

It was found that carbon disulfide copolymerizes with N-(β-cyanoethyl) ethylenimine by using water as a catalyst. The copolymerization was conducted in detail by using water as a catalyst in the temperature range between 0 and 50°C with various initial concentrations of carbon disulfide and N-(β-cyanoethyl)ethylenimine in the absence of solvent. The copolymer obtained was always composed of the two monomers: 1:1 ratio, independent of the initial concentration of the monomers. The copolymer was white solid material soluble in dimethyl sulfoxide, insoluble in other usual organic solvents and decomposed at 155°C. Spectroscopic analysis of the copolymer combined with the results of elemental analysis indicates that the copolymer had the following structure:      

Studies on the synthesis of compounds related to adenosine 3',5'-cyclic phosphate. VII. Synthesis and cardiac effects of N6,N6-dialkyl adenosine 3',5'-cyclic phosphates

A series of novel N6,N6-dialkyl adenosine 3',5'-cyclic phosphates N6,N6-dialkyl cAMPs) was synthesized from 2'-O-p-toluenesulfonyl cAMP (2'-O-tosyl cAMP, 2) and tested for inotropic and chronotropic activities in vitro. Treatment of 2 with excess alkyl halides and sodium hydride followed by detosylation with aqueous NaOH readily gave N6,N6-dialkyl cAMPs (3) in good yields. Various N6,N6-dialkyl cAMPs having different alkyl groups at the N6-position (9-12) were prepared by alkylation followed by detosylation of N6-alkyl-2'-O-tosyl cAMPs (4) which were obtained by the reductive alkylation of 2 with aldehydes in the presence of sodium cyanoborohydride in acetic acid or tosylation of N6-methyl cAMP. The mechanism of the detosylation is briefly discussed. Among the N6,N6-dialkylated derivatives, N6,N6-dipentyl (3f) and N6-ethyl-N6-heptyl (10e) derivatives were found to exhibit a potent positive inotropic effect and a weak positive chronotropic effect. The structure-activity relationships for the position and the length of alkyl residue are discussed.     

Highly sensitive spectrophotometric determination of human serum albumin with 3',4',5',6'-tetrachlorogallein-molybdenum(VI) complex

A highly sensitive spectrophotometric determination of human serum albumin (HSA) with 3',4',5',6'-tetrachlorogallein (T.Cl.Gall)-Mo(VI) complex in a Triton X-100 + polyvinyl alcohol micellar medium is proposed. This method can be used to determine up to ca. 150 micrograms/10 ml of HSA from the optical absorbance at 640 nm, and is superior in sensitivity to the other extremely sensitive spectrophotometric methods. The great sensitivity of this method results from the use of third-derivative spectrophotometry. The binding parameters of T.Cl.Gall-Mo(VI) complex to HSA are n = 77.3 and K = 1.05 x 10(4) M-1 as determined from dual double-reciprocal plots. It is suggested that the colored complex in this system may be the association complex between [HSA]m+ and [MoVI(T.Cl.Gall)2]n- involving hydrophobic interaction between HSA and T.Cl.Gall. The proposed method should also be useful for the detection and determination of some peptides (e.g. low molecular weight peptides containing basic amino acids), as well as proteins.     

N2 Laser-excited luminescence of antiferromagnetically coupled trinuclear chromium(III) complexes

Exchange interaction parameters in several trinuclear chromium(III) complexes [Cr₃O(R-COO)₆(H₂O)₃]X·nH₂O (R = CH₃, C₂H₅) are determined in the study of luminescence, time-resolved luminescence (TRS ), and decay time measurements over the temperature range 4–100°K. The presence of four inequivalent trinuclear clusters and a luminescence anomaly at 25 and 55°K are observed in the basic chromium(III) acetate prisms. Magnetic anomalies reported earlier should be attributed to the distortion and disordering of the hydrogen-bonded channels in crystals at low temperatures.