TMTpro-18plex: The Expanded and Complete Set of TMTpro Reagents for Sample Multiplexing

The
development of the TMTpro-16plex series expanded the breadth
of commercial isobaric tagging reagents by nearly 50% over classic
TMT-11plex. In addition to the described 16plex reagents, the proline-based
TMTpro molecule can accommodate two additional combinations of heavy
carbon and nitrogen isotopes. Here, we introduce the final two labeling
reagents, TMTpro-134C and TMTpro-135N, which permit the simultaneous
global protein profiling of 18 samples with essentially no missing
values. For example, six conditions with three biological replicates
can now be perfectly accommodated. We showcase the 18plex reagent
set by profiling the proteome and phosphoproteome of a pair of isogenic
mammary epithelial cell lines under three conditions in triplicate.
We compare the depth and quantitative performance of this data set
with a TMTpro-16plex experiment in which two samples were omitted.
Our analysis revealed similar numbers of quantified peptides and proteins,
with high quantitative correlation. We interrogated further the TMTpro-18plex
data set by highlighting changes in protein abundance profiles under
different conditions in the isogenic cell lines. We conclude that
TMTpro-18plex further expands the sample multiplexing landscape, allowing
for complex and innovative experimental designs.