Crystallization and preliminary crystallographic analysis of endo-1,3-beta-glucanase from Arthrobacter sp.

Endo-1,3-beta-glucanases hydrolyze internal 1,3-beta-glucosyl linkages. The endo-1,3-beta-glucanase from Arthrobacter sp. was crystallized by the hanging-drop vapour-diffusion method.

Gymnemic acids inhibit rabbit glyceraldehyde-3-phosphate dehydrogenase and induce a smearing of its electrophoretic band and dephosphorylation.

Gymnemic acids (GA) inhibited rabbit muscle glyceraldehyde-3-phosphate dehydrogenase (GAPDH) activity. Binding of GA to GAPDH was observed by surface plasmon resonance measurement. Incubation of GAPDH with GA induced a smearing of the GAPDH band in SDS-PAGE.

Structure of beta-glucan oligomer from laminarin and its effect on human monocytes to inhibit the proliferation of U937 cells.

We analyzed the human monocyte-stimulating ability of laminarin from Eisenia bicyclis, lichenan from Cetraria islandica, and their oligomers depolymerized with endo-1,3-beta-glucanase from Arthrobacter sp. The respective beta-glucan oligomers with different degrees of polymerization (DP) were fractionated from hydrolytic products of laminarin and lichenan using gel-filtration chromatography. The monocyte-conditioned medium pre-cultured in the presence of a fraction of beta-glucan oligomer (DP>/=8) from laminarin exhibited inhibitory activity against the proliferation of human myeloid leukemia U937 cells, while those pre-cultured with other beta-glucan oligomers and the original laminarin and lichenan showed little or no activity.

Effects of alkalinization and ATPase inhibition on stromal free Mg2+ concentration in spinach chloroplasts.

Our earlier studies indicate that stromal alkalinization is essential for light-induced increase in free Mg(2+) concentration ([Mg(2+)]) in chloroplast. Stromal [Mg(2+)] was increased by dark incubation of chloroplasts in the K(+)-gluconate medium (pH 8.0), or by NH(4)Cl.

Kinetic study of the enzymatic cycling reaction conducted with 3alpha-hydroxysteroid dehydrogenase in the presence of excessive thio-NAD(+) and NADH.

We have established a simple kinetic model applicable to the enzyme cycling reaction for the determination of 3alpha-hydroxysteroids. This reaction was conducted under the reversible catalytic function of a single 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) with nucleotide cofactors, thio-NAD(+) (one of the NAD(+) analogues) for the oxidation of 3alpha-hydroxysteroids and NADH for the reduction of 3-oxosteroids. This model was constructed based on the reaction mechanism of 3alpha-HSD, following an ordered bi-bi mechanism with cofactor binding first, under the assumption that the respective enzyme-cofactor complexes were distributed according to the initial ratio of thio-NAD(+) to NADH by the rapid equilibrium of both enzyme-cofactor complexes.

Transient-phase kinetic studies on the nucleotide binding to 3alpha-hydroxysteroid dehydrogenase from Pseudomonas sp. B-0831 using fluorescence stopped-flow procedures.

The dual nucleotide cofactor-specific enzyme, 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD) from Pseudomonas sp. B-0831, is a member of the short-chain dehydrogenase/reductase (SDR) superfamily. Transient-phase kinetic studies using the fluorescence stopped-flow method were conducted with 3alpha-HSD to characterize the nucleotide binding mechanism.

Light-induced increase in free Mg2+ concentration in spinach chloroplasts: measurement of free Mg2+ by using a fluorescent probe and necessity of stromal alkalinization.

Free Mg(2+) in chloroplasts may contribute to the regulation of photosynthetic enzymes, but adequate methodology for the determination of free Mg(2+) concentration ([Mg(2+)]) in chloroplasts has been lacking. We measured internal chloroplast [Mg(2+)] by using a Mg-sensitive fluorescent indicator, mag-fura-2. In intact, dark-kept spinach chloroplasts, internal [Mg(2+)] was estimated to be 0.

Tenascin-C expression and splice variant in habu snake venom-induced glomerulonephritis.

Extracellular matrix glycoprotein tenascin-C (TNC) expression is up-regulated in tissue remodeling processes such as tumorigenesis and wound healing. Mouse tenascin-C contains six alternatively spliced domains (A1, A2, A4, B, C, and D) between the fifth and the sixth type III fibronectin domains, which generate large numbers of TNC isoforms. To study TNC isoform variability of wound healing in mice, we induced glomerulonephritis by using Habu snake venom (HSV) and examined alternatively spliced regions by the reverse transcription polymerase chain reaction (RT-PCR) technique.

PDGF receptor-alpha deficiency in glomerular mesangial cells of tenascin-C knockout mice.

Tenascin-C (TNC) knockout (TNKO) mice showed reduced proliferation of mesangial cells and abnormal restoration after habu-snake venom (HSV)-induced glomerulonephritis. In this study, we examined the relationship of TNC and platelet-derived growth factor receptor (PDGFR) in glomerular mesangial cells. TNC and PDGFR-alpha and -beta transcriptions were up-regulated in wild type (WT) mice after HSV injection, but in TNKO mice PDGFR-alpha transcription was not up-regulated.