We apologize for Proteopedia being slow to respond. For the past two years, a new implementation of Proteopedia has been being built. Soon, it will replace this 18-year old system. All existing content will be moved to the new system at a date that will be announced here.
LiLac - a biosensor for Lactate
From Proteopedia
(Difference between revisions)
| Line 4: | Line 4: | ||
LiLac is a biosensor for lactate with a fluorescence-lifetime readout <ref>DOI 10.1038/s41467-022-30685-x</ref>. The fluorescent protein in LiLac is mTurquoise, a low pKa fluorescent protein commonly used in lifetime-contrast sensors. The ligand-binding protein in LiLac is the lactate-binding Cache domain of TlpC. Cache-domain-containing proteins sense extracellular nutrients to guide chemotaxis in bacteria; the N- and C- termini of the nutrient-sensing regions in Cache proteins (like the lactate-binding region of TlpC) are close in space, facilitating modular design. The combination of this modularity and the large diversity of ligands that Cache domains can sense have made this domain family an attractive starting point for building sensors. The mTurquoise is split in the middle of its seventh β-strand (β7) and then inserted the extracellular domain of TlpC at this position <ref>DOI 10.1038/s41598-017-14372-2</ref>. By engineering the connections between split mTurquoise and TlpC using a microfluidics-based screen, we developed LiLac, a lactate biosensor with a robust ~1.2 ns decrease (−35%) in fluorescence lifetime as lactate binds. | LiLac is a biosensor for lactate with a fluorescence-lifetime readout <ref>DOI 10.1038/s41467-022-30685-x</ref>. The fluorescent protein in LiLac is mTurquoise, a low pKa fluorescent protein commonly used in lifetime-contrast sensors. The ligand-binding protein in LiLac is the lactate-binding Cache domain of TlpC. Cache-domain-containing proteins sense extracellular nutrients to guide chemotaxis in bacteria; the N- and C- termini of the nutrient-sensing regions in Cache proteins (like the lactate-binding region of TlpC) are close in space, facilitating modular design. The combination of this modularity and the large diversity of ligands that Cache domains can sense have made this domain family an attractive starting point for building sensors. The mTurquoise is split in the middle of its seventh β-strand (β7) and then inserted the extracellular domain of TlpC at this position <ref>DOI 10.1038/s41598-017-14372-2</ref>. By engineering the connections between split mTurquoise and TlpC using a microfluidics-based screen, we developed LiLac, a lactate biosensor with a robust ~1.2 ns decrease (−35%) in fluorescence lifetime as lactate binds. | ||
| - | LiLac has the following parts - <scene name='10/1096830/Fp/1'>the split mTurquoise fluorescent core (in magenta colour)</scene>, an N terminal domain , | + | LiLac has the following parts - <scene name='10/1096830/Fp/1'>the split mTurquoise fluorescent core (in magenta colour)</scene>, an N terminal domain, the lactate binding <scene name='10/1096830/Tlpc/1'>TlpC domain</scene>, a <scene name='10/1096830/C_link/1'>C terminal linker</scene> and <scene name='10/1096830/N_link/1'>an N terminal linker</scene>. |
The current report describes the structural aspect of LiLac biosensor (as a part of the course BI3323-Aug2025), and this is entirely adapted from the work entitled " '''State-dependent motion of a genetically encoded fluorescent biosensor'''” by Rosena ''et al'' <ref>DOI 10.1073/pnas.2426324122</ref>. | The current report describes the structural aspect of LiLac biosensor (as a part of the course BI3323-Aug2025), and this is entirely adapted from the work entitled " '''State-dependent motion of a genetically encoded fluorescent biosensor'''” by Rosena ''et al'' <ref>DOI 10.1073/pnas.2426324122</ref>. | ||
---- | ---- | ||
| - | == | + | == Mechanism of action == |
| + | |||
| + | When lactate binds, the fluorescent protein rotates ~150° relative to the TlpC domain and translates by 30 Å as shown. | ||
== Disease == | == Disease == | ||
Revision as of 19:10, 29 November 2025
INTRODUCTION TO A LACTATE SENSOR
| |||||||||||
References
- ↑ doi: https://dx.doi.org/10.1038/s41467-022-30685-x
- ↑ Machuca MA, Johnson KS, Liu YC, Steer DL, Ottemann KM, Roujeinikova A. Helicobacter pylori chemoreceptor TlpC mediates chemotaxis to lactate. Sci Rep. 2017 Oct 26;7(1):14089. doi: 10.1038/s41598-017-14372-2. PMID:29075010 doi:http://dx.doi.org/10.1038/s41598-017-14372-2
- ↑ Rosen PC, Horwitz SM, Brooks DJ, Kim E, Ambarian JA, Waidmann L, Davis KM, Yellen G. State-dependent motion of a genetically encoded fluorescent biosensor. Proc Natl Acad Sci U S A. 2025 Mar 11;122(10):e2426324122. PMID:40048274 doi:10.1073/pnas.2426324122
