Tandem Ubiquitin Binding Entities (TUBEs)
consist of repeated ubiquitin binding domains engineered to increase
affinity and specificity. TUBEs are used for pull-downs from lysates,
Western blots, and fluorescence applications. Currently, our product
line contains K63-, K48-, M1- (linear) and non-selective TUBEs. We are
expanding this line of products to include a TUBE reagent selective for
each polyubiquitin chain linkage.
UbiTest – Is my protein of interest ubiquitylated?
This is one of the most fundamental and common questions that
customers ask us. To answer the question, we put together a
straightforward kit that provides several advantages over traditional
methods. In summary, you pull down ubiquitylated targets with TUBEs,
elute the targets, treat half of the sample with the general
debubiquitylase USP2core, and perform a Western blot for your protein of
interest. USP2core serves as an internal control to demonstrate that
higher molecular weight species were a result of ubiquitylation.
Additionally, some target antibodies do not sensitively recognize the
ubiquitylated target, and USP2core circumvents this issue. We are
expanding this idea to chain-specific applications and you can purchase a
K48 or K63 selective version to investigate chain linkage. UbiTest Alpha is the classic USP2core version, UbiTest Scout adds one linkage-specific DUB, and UbiTest Pack includes all currently available enzymes – USP2core + AMSHcore (K63) + OTUB1 (K48).
UbiQuant S – Measuring specific substrate ubiquitylation
The UbiQuant S kit allows researchers to quantitatively measure ubiquitylation of a specific substrate from cell lysates. (The original UbiQuant
measures total ubiquitylation.) The first version of UbiQuant S is an
ELISA format. We are also developing a high throughput version
utilizing AlphaLISA technology from Perkin Elmer. Additionally, we are
working on versions that detect specific polyubiquitin linkages based on
our TUBE technology.
Protein Production Technology Platform
Rapid advances in genomics and proteomics have led to the discovery
of many novel gene and protein sequences. However, production of
biologically active proteins remains a major bottleneck to the study of
the structure and function of proteins, the generation of therapeutic
proteins, and the identification of novel drug targets. LifeSensors’s
SUMOpro™ fusion technology addresses this bottleneck by enhancing the
expression and solubility of proteins in E. coli and facilitating rapid
purification of biologically active proteins.
The use of the SUMOpro system, however, is restricted to E.coli. The
LifeSensors team has engineered SUMOstar – novel SUMO tags designed
specifically to enhance expression and purification of recombinant
proteins from eukaryotic cells. LifeSensors’s proprietary family of SUMO
and SUMOstar proteases specifically cleave SUMO and SUMOstar tags to
produce native protein with a desired N-terminus, which is very
important in the production of therapeutic proteins. Furthermore,
LifeSensors is developing various affinity matrices, antibodies, and
novel tools for the purification of SUMO-tagged fusion proteins. For
an abbreviated list of publications that used the SUMO tag to purify
proteins click here.
Custom Protein and Peptide Expression and Purification
The development of economically feasible protein production processes
is a major hurdle in taking vaccines, peptides, and therapeutic
proteins from discovery and preclinical development to the market.
LifeSensors has worked with a number of pharmaceutical and biotechnology
companies using its SUMOpro and SUMOstar systems to express and purify
proteins for therapeutic use, as well as for structure and functional
studies. For high value proteins that fail to express in other systems,
the LifeSensors protein production technologies are especially useful.
LifeSensors performs contract expression and purification services based
on FTEs and the value of the protein. The superiority of the
LifeSensors expression system has been demonstrated by:
Enhanced protein production, at least 10–100-fold compared to other systems
Reduced cost owing to restored biological activity and increased yield
Continuous innovation in process development and transfer to GMP production
Deubiquitylases (DUBs) and Ubiquitin-like Protein Enzymes
Protein ubiquitylation is a dynamic process involving a careful
balance between the activity of ubiquitin ligases and their antagonists –
the ubiquitin-specific proteases or deubiquitylating enzymes (DUBs),
which mediate the removal and processing of ubiquitin. Similar to the
ubiquitin pathway, pathways involving ubiquitin-like proteins such as
SUMO, ISG15 and NEDD8 play critical roles in many cellular functions.
Enzymes that remove SUMO (De-SUMOylases), ISG15 (De-ISGinylases), and
NEDD8 (De-NEDDylases) are important targets as biomarkers of disease and
targets for drug discovery. There are approximately 100 DUBs encoded in
the human genome; many of them play critical roles in cellular
physiology. LifeSensors is currently marketing numerous DUBs and their
antibodies, and its ultimate goal is to market all of them. Please view