Compositional protein analysis of high density lipoproteins in hypercholesterolemia by shotgun LC-MS/MS and probabilistic peptide scoring.

A protein of a biological sample is usually quantified by immunological techniques based on antibodies. Mass spectrometry offers alternative approaches that are not dependent on antibody affinity and avidity, protein isoforms, quaternary structures, or steric hindrance of antibody-antigen recognition in case of multiprotein complexes. One approach is the use of stable isotope-labeled internal standards; another is the direct exploitation of mass spectrometric signals recorded by LC-MS/MS analysis of protein digests.

Mass spectrometry-based analytical tools for the molecular protein characterization of human plasma lipoproteins.

Lipoproteins are a heterogeneous population of blood plasma particles composed of apolipoproteins and lipids. Lipoproteins transport exogenous and endogenous triglycerides and cholesterol from sites of absorption and formation to sites of storage and usage. Three major classes of lipoproteins are distinguished according to their density: high-density (HDL), low-density (LDL) and very low-density lipoproteins (VLDL).

No influence of echinocytic shape transformation of erythrocytes on phagocytosis by autologous monocytes in vitro.

The influence of echinocytosis induced by ATP depletion on erythrophagocytosis was analysed. Monocytes were isolated from peripheral blood of healthy, rhesus-positive volunteers and cultured for a total time of 6 h at 37 degrees C with 5% CO2. Erythrocytes from the same donor, either fresh (discocytes) or incubated at 37 degrees C for 48 h (spheroechinocytes) were added.

Quantitative and qualitative analysis of platelet GPIb and von Willebrand factor in liver cirrhosis.

Numerous abnormalities of plasmatic coagulation and platelet function may contribute to the bleeding in liver cirrhosis with a defective platelet-von Willebrand factor interaction being a potential mechanism. To analyze GPIb and von Willebrand factor in cirrhosis, we quantified the number of GPIb molecules on the platelet surface by flow cytometry, assessed the total (and indirectly the internal) pool of GPIb by ELISA and measured the circulating amount of glycocalicin in plasma as a measure of proteolytic activity and platelet turnover. Von Willebrand factor was characterized by ELISA, by its ristocetin-cofactor activity and by multimer analysis.