Postoperative CK-MB and troponin, even at low cutoff levels, are independent and complementary predictors of long-term mortality after major vascular surgery.

No abstract

The purified outer membrane bacterial protein OmcA binds densely to the surface of hematite (Fe2O3), permitting direct electron transfer to this solid mineral to reduce Fe (III) with an electron flux of about 1013 electrons /cm2/s. In the presence of hematite, there is a substantial increase in the amplitude of internal protein motions that correlate with metal reduction. Binding is highly favorable, with a partition coefficient of approximately 2 x 105 (DeltaGo' = -28 kJ/mol), where approximately 1014 OmcA proteins bind per cm2 to the solid metal surface, indicating the utility of using purified OmcA in the construction of a biofuel cell.

Chemical crosslinking combined with mass spectrometry can be a powerful approach for the identification of protein-protein interactions and for providing constraints on protein structures. However, enrichment of crosslinked peptides is crucial to reduce sample complexity before mass spectrometric analysis. In addition compact crosslinkers are often preferred to provide short spacer lengths, surface accessibility to the protein complexes, and must have reasonable solubility under condition where the native complex structure is stable. In this study, we present a novel compact crosslinker that contains two distinct features: 1) an alkyne tag and 2) a small molecule detection tag (NO 2 -) to maintain reasonable solubility in water. The alkyne tag enables enrichment of the crosslinked peptide after proteolytic cleavage after coupling of an affinity tag using alkyne-azido click chemistry. Neutral loss of the small NO 2 -moiety provides a secondary means of detecting crosslinked peptides in MS/MS analyses, providing additional confidence in peptide identifications. We show the labeling efficiency of this crosslinker, which we termed CLIP (Clickenabled Linker for Interacting Proteins) using ubiquitin. The enrichment capability of CLIP is demonstrated for crosslinked ubiquitin in highly complex E. coli cell lysates. Sequential CID-MS/ MS and ETD-MS/MS of inter-crosslinked peptides (two peptides connected with a crosslinker) are also demonstrated for improved automated identification of crosslinked peptides.