alexa MJK2, a K+Channel from M. Jannaschii Mediates pH Depend
ISSN: 2161-0398

Journal of Physical Chemistry & Biophysics
Open Access

Like us on:
OMICS International organises 3000+ Global Conferenceseries Events every year across USA, Europe & Asia with support from 1000 more scientific Societies and Publishes 700+ Open Access Journals which contains over 50000 eminent personalities, reputed scientists as editorial board members.

Open Access Journals gaining more Readers and Citations

700 Journals and 15,000,000 Readers Each Journal is getting 25,000+ Readers

This Readership is 10 times more when compared to other Subscription Journals (Source: Google Analytics)

Research Article

MJK2, a K+Channel from M. Jannaschii Mediates pH Dependent Potassium Transport Activity

Carsten Zeilinger*
Leibniz University of Hannover , Institutfür and Biophysics , Zentrumfür Biomolekulare Wirkstoffchemie ( BMWZ ) , Herrenhäuserstr, 2 , D - 30419 Hannover , Germany
Corresponding Author : Carsten Zeilinger
Leibniz Leibniz University of Hannover, Institutfür and Biophysics
Zentrumfür Biomolekulare Wirkstoffchemie (BMWZ), Herrenhäuserstr, 2
D–30419, Hannover, Germany
Tel: ++49 511 762 4049
E-mail: [email protected]
Received September 2, 2014; Accepted September 22, 2014; Published September 24, 2014
Citation: Zeilinger C (2014) MJK2, a K+ Channel from M. Jannaschii Mediates pH Dependent Potassium Transport Activity. J Phys Chem Biophys 4:156. doi:10.4172/2161-0398.1000156
Copyright: © 2014 Zeilinger C. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


MjK2 was expressed in E. coli cells as a fusion protein containing N-or C-terminal an antibody binding site and a histidinehexamer. The C-terminal tagged fusion protein allows the expression and purification of an extra soluble RCK domain at p34 kDa, whereas this additional RCK domain was lost when the N-terminal tagged construct was used. Upon removal of the fusion peptide from the purified N-terminal tagged channel monomer, MjK2 occurred as a stable tetramer when incubated with synthetic lipid. The channel activity was studied after reconstitution into liposomes by single channel recording or by an optical assay with the potassium sensing dye, PBFI. First the channel function was improved by single channel recording. Single channel recording confirmed the pH dependence of the channel activity with single channel conductances of 42, 70, 85 and 202 pS and indicated that a functional K+ channel was formed. To study the function of the reconstituted MjK2 activity in an optical assay the potassium release was initiated when the external BaCl2 block was compensated by addition of EDTA. The release of potassium was mediated by reconstituted MjK2 at low pH or by the presence of internal calcium at high pH. MgCl2 had no or weak effect, whereas cAMP at low pH caused a complete loss of potassium during the preparation. Alignments studies revealed that MjK2 has different structural features in the channel pore and the RCK composition and therefore a different function can be expected. Amino acid sequence and structural alignments showed that a Ca2+ binding site and a typical nucleotide-binding site is not present in the RCK domain of MjK2 and therefore a different behavior could be expected. In addition a lysine reach linker region as found in human sperm K+ channels hslo1 and hslo3can play similar role in the gating behavior.


Share This Page

Additional Info

Loading Please wait..
Peer Reviewed Journals
Make the best use of Scientific Research and information from our 700 + peer reviewed, Open Access Journals
International Conferences 2017-18
Meet Inspiring Speakers and Experts at our 3000+ Global Annual Meetings

Contact Us

© 2008-2017 OMICS International - Open Access Publisher. Best viewed in Mozilla Firefox | Google Chrome | Above IE 7.0 version