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Full-Text Articles in Physical Sciences and Mathematics
Re-Introduction Of Transmembrane Serine Residues Reduce The Minimum Pore Diameter Of Channelrhodopsin-2, Robert Dempski, Ryan Richards
Re-Introduction Of Transmembrane Serine Residues Reduce The Minimum Pore Diameter Of Channelrhodopsin-2, Robert Dempski, Ryan Richards
Robert E. Dempski
Channelrhodopsin-2 (ChR2) is a microbial-type rhodopsin found in the green algae Chlamydomonas reinhardtii. Under physiological conditions, ChR2 is an inwardly rectifying cation channel that permeates a wide range of mono- and divalent cations. Although this protein shares a high sequence homology with other microbial-type rhodopsins, which are ion pumps, ChR2 is an ion channel. A sequence alignment of ChR2 with bacteriorhodopsin, a proton pump, reveals that ChR2 lacks specific motifs and residues, such as serine and threonine, known to contribute to non-covalent interactions within transmembrane domains. We hypothesized that reintroduction of the eight transmembrane serine residues present in bacteriorhodopsin, but …
The Molecular Determinants Of The Zinc Transporter, Hzip4, Robert Dempski, Sagar Antala, Tuong-Vi Nguyen
The Molecular Determinants Of The Zinc Transporter, Hzip4, Robert Dempski, Sagar Antala, Tuong-Vi Nguyen
Robert E. Dempski
Zinc is an essential micronutrient which is required for the function of hundreds of cellular enzymes. In addition, zinc is the second most abundant transition metal found in biological systems (iron is most abundant). However, the concentration of free zinc is nano to picomolar since most zinc is bound to proteins. This makes investigating the mechanism of zinc transport across the plasma membrane a challenge. Our interest has been to elucidate the mechanism of zinc transport mediated by one member of the ZIP family of proteins, hZIP4.