C(alpha)-formylglycine (FGly) is the catalytic residue in the active site of eukaryotic sulfatases. It is posttranslationally generated from a cysteine in the endoplasmic reticulum. The genetic defect of FGly formation causes multiple sulfatase deficiency (MSD), a lysosomal storage disorder. We purified the FGly generating enzyme (FGE) and identified its gene and nine mutations in seven MSD patients. In patient fibroblasts, the activity of sulfatases is partially restored by transduction of FGE encoding cDNA, but not by cDNA carrying an MSD mutation. The gene encoding FGE is highly conserved among pro- and eukaryotes and has a paralog of unknown function in vertebrates. FGE is localized in the endoplasmic reticulum and is predicted to have a tripartite domain structure.

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The Nef protein of the simian and human immunodeficiency viruses is known to directly bind and downregulate the CD4 receptor. Although the molecular mechanism is well understood, direct binding of Nef and CD4 is difficult to demonstrate and is believed to be of low affinity. Applying nuclear magnetic resonance and fluorescence spectroscopy, we biophysically reevaluated the CD4-Nef complex and found the dissociation constant to be in the submicromolar range. We conclude that additional, so far disregarded residues in the N terminus of Nef are important for interaction with CD4.

Latex of dandelion roots contains a serine proteinase that hydrolyzes a chromogenic peptide substrate Glp-Ala-AlaLeu-pNA optimally at pH 8.0. Maximal activity of the proteinase in the roots is attained in April, at the beginning of plant development after the winter period. The protease was isolated by ammonium sulfate precipitation of the root extract followed by affinity chromatography on a Sepharose-Ala-AlaLeu-mrp and gel filtration on Superose 6R performed in FPLC regime. Pure serine proteinase named taraxalisin was inactivated by specific inhibitors of serine proteinases, diisopropylfluorophosphate (DFP) and phenylmethylsulfonylfluoride (PMSF). Its molecular mass is 67 kDa and pI 4.5. pH stability range is 6^9 in the presence of 2 mM Ca P+ , temperature optimum is at 40³C; K m =0.37 þ 0.06 mM. The substrate specificity of taraxalisin towards synthetic peptides and insulin B-chain is comparable with that of two other subtilisin-like serine proteinases, cucumisin and macluralisin. The taraxalisin N-terminal sequence traced for 15 residues revealed 40% coinciding residues when aligned with that of subtilisin Carlsberg.z 1998 Federation of European Biochemical Societies.

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-012Silver-Ion Conduction Pathways in Ag 5 IP 2 O 7 . -The title compound, which is the compound with the lowest AgI content in the quasi-binary AgIAg 4 P 2 O 7 system, is prepared by melting a mixture of AgI and Ag 4 P 2 O 7 and subsequent annealing at 773 K (evacuated tube, 2 h). Ag 5 IP 2 O 7 crystallizes in the orthorhombic space group P2 1 2 1 2 1 with Z = 4. All silver ions are found to be coordinated by both diphosphate and iodide anions. Ag 5 IP 2 O 7 is a moderate Ag + ion conductor with an activation energy of 0.28 eV and a room temp. conductivity of 3·10 −6 Ω −1 cm −1 . The Ag + ion conduction pathways in this solid electrolyte are modeled by the bond-valence technique.

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Abstract. This paper analyses the influence of 13 stylized facts of the German economy on the West German business cycles from 1955 to 1994. The method used in this investigation is Statistical Experimental Design with orthogonal factors. We are looking for all existing Plackett-Burman designs realizable by coded observations of these data. The plans are then analysed by regression with forward selection and various classification methods to extract the relevant variables for separating upswing and downswing of the cycles. The results are compared with already existing studies on this topic.