Sodium-potassium adenosine triphosphatase: acyl phosphate "intermediate" shown to be L-glutamyl-gamma-phosphate

Peptides obtained from pepsin digestion of the phosphorylated and nonphosphorylated forms of a preparation of brain microsomal sodium-potassium-activated adenosine triphosphatase were treated at pH 5.4 with N-(n-propyl-2,3-(3)H) hydroxylamine of high specific activity, then separated by column chromatography, and further digested with pronase. A compound isolated in higher amounts from the phosphorylated enzyme than from the nonphosphorylated enzyme migrated with authentic L-glutamyl-gamma-propylhydroxamate in four chromatographic systems and on electrophoresis on paper at three different pH's. The acyl phosphate "intermediate" in the phosphorylated form of the adenosine-triphosphatase therefore appears to be an L-glutamyl-gamma-phosphate residue.     

农民朋友,上网小心"网络钓鱼"

随着网络应用的迅速普及，“网络钓鱼”形式的网络欺诈案件给不少企业和个人用户带来了巨大的经济损失。本文结合具体案例，较为全面地剖析了网络骗子们常用的手段和方法，详细介绍了在进行电子商务活动时，怎样防范“网络钓鱼”。     

Comment on "Ongoing adaptive evolution of ASPM, a brain size determinant in Homo sapiens" and "Microcephalin, a gene regulating brain size, continues to evolve adaptively in humans"

Mekel-Bobrov et al. and Evans et al. (Reports, 9 Sept. 2005, p. 1720 and p. 1717, respectively) examined sequence data from modern humans within two gene regions associated with brain development, ASPM and microcephalin, and concluded that selection of these genes must be ongoing. We show that models of human history that include both population growth and spatial structure can generate the observed patterns without selection.     

Comment on "Obestatin, a peptide encoded by the ghrelin gene, opposes ghrelin's effects on food intake"

Zhang et al. (Research Articles, 11 November 2005, p. 996) reported that obestatin, a peptide derived from the ghrelin precursor, activated the orphan G protein-coupled receptor GPR39. However, we found that I125-obestatin does not bind GPR39 and observed no effects of obestatin on GPR39-transfected cells in various functional assays (cyclic adenosine monophosphate production, calcium mobilization, and GPR39 internalization). Our results indicate that obestatin is not the cognate ligand for GPR39.     

解决"三农"问题需抓好几个重大而实际的问题

“三农”问题一直是群众反映强烈的重大问题，也是全党关注的重点问题。这不仅因为“三农”问题是我国经济发展中的突出问题，而且更重要地还是我国政治、社会的重要问题。笔者在深入农村调查研究中，对“三农”问题进行了深刻思考，认为解决“三农”问题需抓好以下几个重大而实际的问题。