3-Hexulosephosphate synthase from Methylomonas aminofaciens 77a. Purification, properties and kinetics

3-Hexulosephosphate synthase (D-arabino-3-hexulose 6-phosphate formaldehyde lyase) was purified from an obligate methylotroph, Methylomonas aminofaciens, to homogeneity as judged by polyacrylamide gel electrophoresis and analytical ultracentrifugation. The molecular weight was determined to be 45 000-47 000 by sedimentation velocity and gel filtration. The enzyme appears to be composed of two identical subunits (Mr = 23 000). A bivalent cation is required for the activation and stabilization of the enzyme. The enzyme is specific for formaldehyde and D-ribulose 5-phosphate. The optimum pH is 8.0 (isoelectric point, pH 5.1) and the optimum temperature is 45 degrees C. Initial velocity studies are consistent with a sequential mechanism. The Michaelis constants are 0.29 mM for formaldehyde and 0.059 mM for D-ribulose 5-phosphate.     

Description of bovine major histocompatibility complex class IIa haplotypes using parthenogenetic embryo‐derived cells

In this study, we report an approach to characterize individual BoLA haplotypes using cells from parthenogenetic bovine embryos derived from slaughterhouse ovaries. Eight of the 15 parthenogenetic embryos so obtained had not undergone meiotic recombination on the BoLA region and were suitable to describe BoLA haplotypes. Detailed analysis of the BoLA class IIa region identified seven different class IIa haplotypes, including six not previously described and two new alleles of BoLA‐DQA and one BoLA‐DQB. Our method provided reliable sources of homozygous DNA to describe BoLA haplotypes.     

Synthesis of N-Carbamyl-d-2-thienyl-glycine and d-2-Thienylglycine by Microbial Hydantoinase

A debranching enzyme purified from germinating rice endosperm hydrolyzed oligosaccharides having maltosyl or maltotriosyl branches (B₄-B₆) moderately. Hydrolysis of maltosylmaltose by a “pullulanase” of higher plant origin has been scarcely reported, while our enzyme debranched maltosylmaltose like microbial pullulanase. Additionally, the enzyme slowly hydrolyzed isopanose to glucose and maltose.

Gel-filtration analyses of hydrolysis products of polysaccharides with the enzyme suggested that while it hydrolyzed α-1,6-linkages of pullulan at random, it hydrolyzed amylopectin and glycogen at the outer α-1,6-linkages preferentially In the hydrolysis products of glycogen with the enzyme for a longer incubation time, large molecular-weight glucans still remained. This indicated that the enzyme was able to hydrolyze a few of the α-1,6-linkages of glycogen.     

Behavior of filamentous temperature-sensitive Z2 (FtsZ2) in the male gametophyte during sexual reproduction processes of flowering plants

Protoplasma - Filamentous temperature-sensitive Z (FtsZ) is a critical division protein in bacteria that functions in forming a Z-ring structure to constrict the cell. Since the establishment of...     

A Novel Time-Dependent CENP-E Inhibitor with Potent Antitumor Activity

Centromere-associated protein E (CENP-E) regulates both chromosome congression and the spindle assembly checkpoint (SAC) during mitosis. The loss of CENP-E function causes chromosome misalignment, leading to SAC activation and apoptosis during prolonged mitotic arrest. Here, we describe the biological and antiproliferative activities of a novel small-molecule inhibitor of CENP-E, Compound-A (Cmpd-A). Cmpd-A inhibits the ATPase activity of the CENP-E motor domain, acting as a time-dependent inhibitor with an ATP-competitive-like behavior. Cmpd-A causes chromosome misalignment on the metaphase plate, leading to prolonged mitotic arrest. Treatment with Cmpd-A induces antiproliferation in multiple cancer cell lines. Furthermore, Cmpd-A exhibits antitumor activity in a nude mouse xenograft model, and this antitumor activity is accompanied by the elevation of phosphohistone H3 levels in tumors. These findings demonstrate the potency of the CENP-E inhibitor Cmpd-A and its potential as an anticancer therapeutic agent.     

Fluvastatin depresses the enhanced lipid peroxidation in vitamin E-deficient hamsters

Fluvastatin, a 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitor, has recently been reported to have the antioxidative activity in vitro. However, it is still unclear whether chronic treatment with this drug actually leads to amelioration of the redox status in the body. In this study, we investigated the antioxidative effect of fluvastatin in vivo, using a vitamin E-deficient hamster model, an in vivo model of enhanced oxidative stress. After pre-treatment with a vitamin E-deficient diet for 2 months, fluvastatin, pravastatin or probucol was added to the diet for 1 month. Vitamin E deficiency caused a significant increase in the levels of plasma oxidative stress markers such as 8-iso-prostaglandin F2α (8-iso-PGF2α) and hydroperoxides. Furthermore, there was a significant increase in the oxidizability of plasma lipids in the vitamin E-deficient animals, indicating that the oxidative stress was increased in the circulation. Fluvastatin markedly depressed the above oxidative stress markers in plasma, and significantly decreased the oxidizability of plasma lipids without affecting their levels. Probucol, a reference antioxidant, also showed a similar effect while pravastatin, another HMG-CoA reductase inhibitor, showed only a weak improvement. We suggest that the treatment with fluvastatin leads to a reduction of oxidative stress in vivo, which is mainly derived from its antioxidative property rather than its lipid-lowering activity.