Purification and characterization of a phosphatidylinositol 4-kinase from bovine uteri

Phosphatidylinositol 4-kinase has been purified 10,148-fold to a specific activity of 2.7 mumol/mg/min from bovine uteri. This purification was accomplished by detergent extraction of an acetone powder, ammonium sulfate precipitation, and chromatography on MonoQ, S-Sepharose, MonoP, and hydroxylapatite columns. The purified enzyme has a molecular mass of 55 kDa and appears to be monomeric. Kinetic analyses of the enzymatic activity demonstrated apparent Km values of 18 microM and 22 micrograms/ml (approximately 26 microM) for ATP and phosphatidylinositol, respectively, optimal activity in the pH range of 6.0-7.0, and a sigmoidal dependence of enzymatic activity on [Mg2+]. Ca2+ inhibited the enzyme at nonphysiological concentrations with 50% inhibition observed at a free [Ca2+] of approximately 300 microM. The purified enzyme efficiently utilized both ATP and 2'-deoxy-ATP as phosphoryl donors and specifically phosphorylated phosphatidylinositol on the fourth position. No phosphatidylinositol-4-phosphate 5-kinase activity was observed in the purified enzyme preparations. To our knowledge, this is the first reported purification of a phosphatidylinositol-specific phosphatidylinositol 4-kinase.     

Preliminary results on nematicidal activity from culture filtrates of Basidiomycetes against the pine wood nematode,Bursaphelenchus xylophilus (Aphelenchoididae)

One hundred and eighty one fungal species that were isolated from the fresh fruiting bodies collected in the Mountains of Pu Er County of Yunnan Province, China were tested on the pine wood nematode,Bursaphelenchus xylophilus in vitro. Each fungal species was grown in Czapek broth and potato dextrose broth (PDB). Fifteen filtrates fromAmauroderma austrosinense, Amauroderma macer, Filoboletus sp.,Laccaria tortilis, Lactarius gerardii, Lentinula edodes, Oudemansiella longipes, Oudemansiella mucida, Peziza sp.,Pleurotus sp.,Sinotermitomyces carnosus (two strains),Strobilomyces floccopus, Termitomyces albuminosus, Tylopilus striatulus grown on PDB were found to be pathogenic to the tested nematodes. Eleven filtrates fromAmanita junguillea, Amanita sp.,Daedalea sepiaria, Fistulina hepatica, Omphalotus olearius, Oudemansiella mucida, Peziza sp.,Pleurotus pulmatus, Ramaria sp.,Tricholoma conglobatum, Tylopilus striatulus grown on Czapek broth were also pathogenic to the nematodes. When screening for nematicidal potential of fungi, it is important to study the growth medium conditions necessary to obtain the optimal nematicidal effect as fungal filtrates growing on different liquid media showed a very inconsistent toxicity towards nematodes.     

Comparative Effects of Hispidulin,Genistein, and Icariin with Estrogen on Bone Tissue in Ovariectomized Rats

Icariin, Genistein, and Hispidulin have been proven to have estrogen-like and antiosteoporotic activity and can be potentially used for the treatment of osteoporosis. The present study found that Icariin, Genistein, and Hispidulin treatments, emulating estrogen, significantly contributed to bone density. Comparative effects of Icariin, Genistein, and Hispidulin with estrogen on in ovariectomized rats were investigated. Our results showed that genistein was found to have superior bone protective effects against osteoporosis among genistein, Icariin, and Hispidulin.     

A modified Coomassie Brilliant Blue staining method at nanogram sensitivity compatible with proteomic analysis

A more sensitive and convenient Coomassie Brilliant Blue (CBB) staining method for visualizing proteins was developed. Compared with the modifications include the supplement of 10% (v/v) methanol into the fixing solution, an increase of an additional sensitization step and CBB raised from 0.1 to 0.125%. The improved method can detect proteins at nanogram level. The improved method is more sensitive than Blue Silver and more convenient than the Silver protocol. Mass spectrometry results confirmed that it is suitable for subsequent proteomic research.     

Stress-induced RNASET2 overexpression mediates melanocyte apoptosis via the TRAF2 pathway in vitro

The recent genome-wide association study identified a link between vitiligo and genetic variants in the ribonuclease T2 (RNASET2) gene; however, the functional roles of RNASET2 in vitiligo pathogenesis or in melanocyte apoptosis have yet to be determined. The current study was designed to investigate the vitiligo-related expression pattern of RNASET2 and its molecular function involving apoptosis-related signaling proteins and pathways. The results showed overexpression of RNASET2 in epidermis specimens from 40 vitiligo patients compared with that from matched healthy controls. In addition, in vitro analyses indicated that overexpression of RNASET2 was inducible in cultured primary human melanocytes and keratinocytes by stress conditions, that is, exposure to UV irradiation, hydrogen peroxide, and inflammatory factors, respectively, and led to increased cell apoptosis via the tumor necrosis factor receptor-associated factor 2 (TRAF2)–caspases pathway through the physical interaction of RNASET2 with TRAF2. Thus, RNASET2 may contribute to vitiligo pathogenesis by inhibiting TRAF2 expression and, as such, RNASET2 may represent a potential therapeutic target of vitiligo.