Integrated Calendar

It is a pleasure to invite you to the "Shirat Hamada" Evening for 2014, in Memory of Prof. Ofer Lider. The event will take place on Thursday, January 15 at 19:30 at the Wix Auditorium, Weizmann Institute of Science. We would be happy to see you among our guests.

Yours sincerely,
Amutat "Shirat Hayav"

Ubiquitin (Ub) is a highly stable small protein, and its structure is evolutionary conserved from yeast to human. Ub attaches to its protein substrate via one or multiple Lysines, modifying the target as mono- or multi-ubiquitination. The specific Lysine linkage type has different biological significance, serving as signal to target proteins for degradation by the proteasome or in lysosomes or modulating protein function or localization. A main challenge in the ubiquitin field is to identify the polyUb chain type on a particular substrate, in vivo and in vitro. Researches often employ Western blot analysis using linkage-specific antibodies, which their recognition epitope lies in the ubiquitin linkage site. However, producing antibodies with high reactivity and specificity is a highly laborious and complicated process, and not readily extended to the single molecules level.
Nanopores are single molecule sensors, which utilize an electrophoretic focusing and transport of biomolecules through a nanoscale pore formed in a thin membrane. Nanopores fabricated in solid-state substrates were proven to be among the most sensitive nucleic acids biosensors. But the detection of individual small proteins has been challenging so far, primarily due to the poor signal to noise ratio that these molecules produce during their passage through the pore. Here we show that fine adjustments of the buffer’s acidity close to the analytes’ isoelectric point can be used to slow down the translocation speed of the analytes, hence permitting sensing and characterization of small globular proteins. Applying our method to the detection of mono and poly-Ub molecules, we show that we can discriminate among two equal molecular weight di-Ub conformers, which only posses a slightly different 3D structure due to a different Lysine linkage location. Our method opens up a novel approach for analyzing proteins at unprecedented detail using solid-state nanopores. It serves as a proof of concept for approaching nanopore detection of sub 10 kDa proteins and its ability to differentiate among native individual proteins of the same amino acid sequence.

Dept of Neurobiology-Students & Postdocs Seminar
Benoziyo Brain Research Building - Room 113

Israeli songs
Raphael Kadishzon - conductor
Keren Hadar - vocal

Free Entrance