Application of MeCAT-Click labeling for protein abundance characterization of XXXX after heat shock experiments.

@entity575 @entity37461 @entity3928 @entity17361 @entity15 @entity526
UNASSIGNED: In a proof of concept study, metal-coded affinity tags based on click chemistry (MeCAT-Click) were used to analyze the proteome of @entity526 (E.coli) in response to heat stress. This allows high labeling efficiency, high detection sensitivity, and multiplex capabilities, which are pivotal for its application to protein quantification. Two approaches are presented for relative quantification of differentially @entity17361 -labeled proteins. The first approach uses isotope-labeling, where ESI- @entity15 was utilized to quantify the differentially labeled proteins from different states of @entity526 . With this approach, 14 proteins were found with changed abundance, among them five proteins upregulated. In the second approach, differentially labeled samples were separated by two dimensional gel electrophoresis (2-DE) and scanned by @entity3928 ( @entity3928 ). Comparison of the signal intensities of the different @entity37461 was used to quantify different sample states. Based on this information, ESI- @entity15 was used to identify the proteins with different abundance. The sensitivity of @entity3928 allowed us to find one upregulated protein that was nearly invisible by @entity575 staining ("Probable replication endonuclease from retron EC67"). The advantage of this approach is to locate low abundant proteins with differential expression using @entity3928 , which may be overlooked otherwise. BIOLOGICAL SIGNIFICANCE: This paper demonstrates the successful application of a novel metal labeling strategy to quantify the proteins from complex biological samples. In comparison with former metal labeling strategies, it reduces the steric hindrance and improves the labeling efficiency during the labeling process, which ensure its successful application. This methodology is compatible with both molecular and elemental mass spectrometry. ESI- @entity15 / @entity15 in combination with software-based search allows the identification and relative quantification of labeled proteins. In addition, @entity3928 helps to locate the labeled proteins in 2-DE gels with superior detection capability, thus, target proteins with low abundance can be precisely followed. Its excellent sensitivity allows one to track the proteins of interest that are barely visible by @entity575 staining.
