Metabolomics, also known as Metabolic Profiling, is an emerging discipline under the umbrella concept of systems biology. The goal of metabolomics is to know and understand the concentrations and fluxes of endogenous metabolites within a living biological system under study. General tools are being developed for the rapid measurement of many metabolites in a single experiment, most of which are mass spectrometric methods. FT-ICR has unique advantages, as a mass spectrometric method, in this regard. Applications of FT-ICR to metabolomics analyses will be discussed and reviewed in the context of the single publication currently available.

AimHigh-density lipoproteins (HDLs) have several potentially protective vascular effects. Most clinical studies of therapies targeting HDL have failed to show benefits vs. placebo.ObjectiveTo investigate the effects of an HDL-mimetic agent on atherosclerosis by intravascular ultrasonography (IVUS) and quantitative coronary angiography (QCA).Design and settingA prospective, double-blinded, randomized trial was conducted at 51 centres in the USA, the Netherlands, Canada, and France. Intravascular ultrasonography and QCA were performed to assess coronary atherosclerosis at baseline and 3 (2–5) weeks after the last study infusion.PatientsFive hundred and seven patients were randomized; 417 and 461 had paired IVUS and QCA measurements, respectively.InterventionPatients were randomized to receive 6 weekly infusions of placebo, 3 mg/kg, 6 mg/kg, or 12 mg/kg CER-001.Main outcome measuresThe primary efficacy parameter was the nominal change in the total atheroma volume. Nominal changes in per cent atheroma volume on IVUS and coronary scores on QCA were also pre-specified endpoints.ResultsThe nominal change in the total atheroma volume (adjusted means) was −2.71, −3.13, −1.50, and −3.05 mm3 with placebo, CER-001 3 mg/kg, 6 mg/kg, and 12 mg/kg, respectively (primary analysis of 12 mg/kg vs. placebo: P = 0.81). There was also no difference among groups for the nominal change in per cent atheroma volume (0.02, −0.02, 0.01, and 0.19%; nominal P = 0.53 for 12 mg/kg vs. placebo). Change in the coronary artery score was −0.022, −0.036, −0.022, and −0.015 mm (nominal P = 0.25, 0.99, 0.55), and change in the cumulative coronary stenosis score was −0.51, 2.65, 0.71, and −0.77% (compared with placebo, nominal P = 0.85 for 12 mg/kg and nominal P = 0.01 for 3 mg/kg). The number of patients with major cardiovascular events was 10 (8.3%), 16 (13.3%), 17 (13.7%), and 12 (9.8%) in the four groups.ConclusionCER-001 infusions did not reduce coronary atherosclerosis on IVUS and QCA when compared with placebo. Whether CER-001 administered in other regimens or to other populations could favourably affect atherosclerosis must await further study.Name of the trial registry: Clinicaltrials.gov; Registry's URL: ; Trial registration number: NCT01201837.

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ClinicalTrials.gov Identifier: NCT2484378.

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An original serie of 12-to 22-residue-long peptides was developed, they are only constituted by apolar Leu and charged Lys residues periodically located in the sequence in order to generate ideal highly amphipathic a-he&s. By circular dichroism, the peptides are proven to be mainly a-helical in organic and aqueous solvents and in the presence of lipids. The peptides are highly hemolytic, their activity varies according to the peptide length. The IS-, 20-, and 22-residue-long-peptides have LD,, -5 x lo-' M for IO'erythrocytes, i.e. they are 5-10 times more active than melittin, and are indeed several orders of magnitude more active than magainin or mastoparan.

In order to gain some insight into the mechanism of insertion into membranes of the pore-forming domain of colicin A and the structure of its membrane-bound form, circular dichroism (in the near and far ultraviolet), fluorescence and ultraviolet spectroscopy experiments were carried out. Because the structure of the water-soluble form of this fragment has been determined by X-ray crystallography, these spectroscopic methods provided valuable information on the secondary structure and the environment of aromatic residues within the two forms of the peptide. These results strongly suggest that the pore-forming domain of colicin A does not undergo drastic unfolding upon insertion into membrane. The conformational change associated with this process is triggered by the negatively charged lipids and probably consists of a reorientation of helix pairs with respect to each other. Exposure of the aromatic residues to the aqueous phase decreases on binding to lipids whilst the exposure of the tryptophans to the membrane phase increases. This cannot occur without a reorientation of helices 3 -10. All data from this study support the model presented previously in which the known crystal structure opens like an 'umbrella' inserting the hydrophobic hairpin (helix 8 -9) perpendicular to the membrane plane and the helical pair 1-2 and the domain containing the three tryptophans (helices 3-7) lying more or less parallel to the membrane plane. Lipids are bound more tightly to the protein at acidic pH than at neutral pH although a similar lipid protein complex is formed with 1,2-dimyristoyl-sn-glycero(3)-phospho(l)-sn-glycerol at both pH values.Colicins are plasmid-encoded protein antibiotics which kill bacteria closely related to the producing strain (generally Escherichia coli). Like many toxins, colicins are composed of structural domains specialized in one of the different steps of the activity i.e. targeting, translocation and killing. The major group of colicins is the E l class, comprised of colicins A, B, El,

In a minimalist approach to modeling lytic toxins, amphipathic peptides of LiKj with i=2j composition and whose length varies from 5 to 22 residues were studied for their ability to induce hemolysis and lipid vesicle leakage. Their sequences were designed to generate ideally amphipathic alpha helices with a single K residue per putative turn. All the peptides were lytic, their activities varying by more than a factor of 103 from the shortest 5-residue-long peptide (5-mer) to the longest 22-mer. However, there was no monotonous increase versus length. The 15-mer was as active as the 22-mer and even more than melittin which is used as standard. Partition coefficients from the buffer to the membrane increased in relation to length up to 12 residues, then weakly decreased to reach a plateau, while they were expected to increase monotonously with peptide length and hydrophobicity as revealed from HPLC retention times. Fluorescence labeling by a dansyl group at the N-terminus, or by a W near the CO-terminus, show that up to 12 residues, the peptides were essentially monomeric while longer peptides strongly aggregated in the solution. Lipid affinity was then controlled by peptide length and was found to be limited by folding and self-association in buffer. The lytic activity resulted both from lipid affinity, which varied by a factor of 20-fold, and from efficiency in disturbing the membrane when bound, the latter steeply and monotonously increasing with length. The 15-residue-long peptide, KLLKLLLKLLLKLLK, had the optimal size for highest lytic activity. The shallow location of the fluorescent labels in the lipids is further evidence for a model of peptides remaining flat at the interface.