We have previously identified, in three British families having an index child with frequent infections, a point mutation (GGC-->GAC) in codon 54 of exon 1 of the gene for the human lectin mannose binding protein (MBP). This was associated with low serum levels of this complement activating protein and would be anticipated to impair opsonization of mannose rich microorganisms. We now report a second point mutation (GGA-->GAA) in Gambians from West Africa, involving codon 57 of exon 1. By substituting carboxylic acids for axial glycines in the translated proteins both mutations would be expected to disrupt the secondary structure of the collagenous triple helix of the 96 kDa MBP subunits. In the Gambians the codon 57 mutation was studied by PCR, sequence analysis and restriction analysis and found to be remarkably common (frequency of the mutant gene 0.29 in adults and 0.23 in newborns) whereas the codon 54 mutation was very rare (frequency 0.003). However, the codon 54 mutation was frequent in both a British Caucasian and a Hong Kong Chinese population (frequency of the mutant gene 0.17 and 0.11 respectively). It was predicted that both homozygous and heterozygous individuals would have profoundly reduced serum levels of the protein and this was confirmed by immunoassay as was the reduced capacity of such sera to activate complement through the MBP initiated classical pathway. Our data indicate that the two mutations have arisen independently since the divergence of African and non African populations and both have attained high frequencies.

Venoms have evolved over millions of years into potent cocktails of bioactive peptides and proteins. These compounds can be of great value to the pharmaceutical industry for numerous clinical applications. In this study, a novel proteomic - bioinformatic approach was utilised, where chromatography followed by gel electrophoresis was utilised to separate the venom peptides/proteins of Heterometrus longimanus (Asian black scorpion). Purified peptides were analysed by tandem mass spectrometry, de novo sequenced and then homology matched against known peptides in the Swiss-Prot protein database. Numerous potentially biologically active peptide matches were discovered, and a simple scoring system applied to putatively assign functions to the peptides. As a validation of this approach, the functional composition of the experimentally derived proteome is similar to that of other scorpions, and contains a potent mix of toxins, antimicrobials and ionic channel inhibitors.

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The current study has identified novel plasma biomarkers (apoA4, CD5L, C1QB, and IBP3) that may improve the prediction of rapid decline in renal function independently of recognized clinical risk factors in type 2 diabetes.

Interleukin-5 (IL-5) is the major cytokine regulating eosinophil production. In allergic disease tissue damage is primarily caused by eosinophils. Heparan sulfate proteoglycans are components of the bone marrow stroma, which supports hemopoietic cell differentiation and proliferation. We show that at low IL-5 concentrations heparan sulfate enhances the proliferation of an IL-5-dependent cell line. To investigate a mechanism for this effect we used an artificial proteoglycan to establish an enzyme-linked immunosorbent assay for the binding of heparin to proteins. Using this assay we demonstrate that IL-5 binds to heparin. The IL-5/heparin interaction is inhibited by ethylenediaminetetraacetate and enhanced by low concentrations of zinc ions. IL-5 interacts with iduronic acid containing glycosaminoglycans, and heparan sulfate preparations that have numerous N-sulfated domains per chain are especially efficient at inhibiting heparin binding. Both IL-5/ heparin binding and the synergistic effect of IL-5 and heparan sulfate on cell proliferation were inhibited by an anti-IL-5 monoclonal antibody. These data suggest that the binding of IL-5 to heparan sulfate modulates IL-5 activity.