[Biofizika] Seminar @IRB: S. Yitzchaik, 22.2. (četvrtak) 14h (c.t.), seminar ZTF-a

[Tomislav Vuletic]

Dragi biofizicari,

ukazao bih na seminar od interesa nasoj zajednici. (neka vas ne zasmeta 
što je oglašen kao seminar teor. fizike)

Lp,

T. Vuletic



-------- Forwarded Message --------

                  SEMINAR  TEORIJSKE  FIZIKE


     (Zajednički seminari Fizičkog odsjeka PMF-a te Zavoda za teorijsku
      fiziku i Zavoda za eksperimentalnu fiziku IRB-a)

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       Conformationally Adaptive Biosensors


       S. Yitzchaik
       Institute of Chemistry and the Center for Nanoscience and
       Nanotechnology,
       the Hebrew University of Jerusalem



     Datum:  četvrtak, 22. veljače 2018.
     Vrijeme: 14 sati c.t.
     Mjesto: IRB, predavaona III krila


    Sažetak:

      In this contribution we’ll exemplified the usefulness of label
free electrochemical biosensors that utilizes proteins and peptides
conformational changes for improved biosensing. Molecular recognition
events accompanied with conformational alternation are prone to
undergo collective structural change when assembled in monolayers.
This phenomenon is demonstrated for ions, small molecules and proteins
biosensing. A case study for neurodegenerative disease will be
described in depth.
Zinc and copper are essential metal ions for numerous biological
processes. Their levels are tightly maintained in all body organs.
Impairment of the Zn2+ to Cu2+ ratio in serum was found to correlate
with many disease states, including immunological and inflammatory
disorders. Oxytocin (OT) is a neuropeptide, and its activity is
modulated by zinc and copper ion binding. Harnessing the intrinsic
properties of OT is one of the attractive ways to develop valuable
metal ion sensors. In this talk, we report an OT-based metal ion
sensor prepared by immobilizing the neuropeptide onto a glassy carbon
electrode. The developed impedimetric biosensor was ultrasensitive to
Zn2+ and Cu2+ ions at physiological pH and not to other biologically
relevant ions. Interestingly, the electrochemical impedance signal of
two hemicircle systems was recorded after the attachment of OT to the
surface. These two semicircles suggest two capacitive regions that
result from two different domains in the OT monolayer. Moreover, the
change in the charge-transfer resistance of either Zn2+ or Cu2+ was
not similar in response to binding. This suggests that the
metal-dependent conformational changes of OT can be translated to
distinct impedimetric data. Selective masking of Zn2+ and Cu2+ was
used to allow for the simultaneous determination of zinc to copper
ions ratio by the OT sensor. The OT sensor was able to distinguish
between healthy control and multiple sclerosis patients diluted sera
samples by determining the Zn/Cu ratio similar to the state-of-the-art
techniques. The OT sensor presented herein is likely to have numerous
applications in biomedical research and pave the way to other types of
neuropeptide-derived sensors.






Voditelj seminara: Anđelo Samsarov (asamsarov at irb.hr)

http://thphys.irb.hr/Seminar/list.htm

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