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Glucose recognition proteins for glucose sensing at physiological concentrations and temperatures.

Joel S, Turner KB, Daunert S - ACS Chem. Biol. (2014)

Bottom Line: The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins.The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability.This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami , 1011 NW 15th Street, Miami, Florida 33136, United States.

ABSTRACT
Advancements in biotechnology have allowed for the preparation of designer proteins with a wide spectrum of unprecedented chemical and physical properties. A variety of chemical and genetic methods can be employed to tailor the protein's properties, including its stability and various functions. Herein, we demonstrate the production of semisynthetic glucose recognition proteins (GRPs) prepared by truncating galactose/glucose binding protein (GBP) of E. coli and expanding the genetic code via global incorporation of unnatural amino acids into the structure of GBP and its fragments. The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins. The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability. These modifications enabled the utilization of the protein for the detection of glucose within physiological concentrations (mM) and temperatures ranging from hypothermia to hyperthermia. This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring.

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Related in: MedlinePlus

Response of GBP H152C (green), tGRP1 (red), and tGRP2 (blue) todifferent sugars (100 mM). Data are the average of ±1 SD (n = 3).
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fig3: Response of GBP H152C (green), tGRP1 (red), and tGRP2 (blue) todifferent sugars (100 mM). Data are the average of ±1 SD (n = 3).

Mentions: Disrupting the first- and second-shell amino acidscould also affect the selectivity of the proteins, causing them torespond to sugar molecules other than glucose and galactose. Giventhat the overall structure became less stable, it could be possiblethat the binding pocket became more flexible and able to accommodateother similarly shaped ligands. To investigate this, a selectivitystudy with MDCC-labeled tGRPs was carried out with a variety of physiologicallyrelevant sugar molecules (Figure 3). As withnative GBP, tGRPs responded best to glucose and to a lesser degreeto galactose. None of the other sugar molecules showed a significantresponse.


Glucose recognition proteins for glucose sensing at physiological concentrations and temperatures.

Joel S, Turner KB, Daunert S - ACS Chem. Biol. (2014)

Response of GBP H152C (green), tGRP1 (red), and tGRP2 (blue) todifferent sugars (100 mM). Data are the average of ±1 SD (n = 3).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4215909&req=5

fig3: Response of GBP H152C (green), tGRP1 (red), and tGRP2 (blue) todifferent sugars (100 mM). Data are the average of ±1 SD (n = 3).
Mentions: Disrupting the first- and second-shell amino acidscould also affect the selectivity of the proteins, causing them torespond to sugar molecules other than glucose and galactose. Giventhat the overall structure became less stable, it could be possiblethat the binding pocket became more flexible and able to accommodateother similarly shaped ligands. To investigate this, a selectivitystudy with MDCC-labeled tGRPs was carried out with a variety of physiologicallyrelevant sugar molecules (Figure 3). As withnative GBP, tGRPs responded best to glucose and to a lesser degreeto galactose. None of the other sugar molecules showed a significantresponse.

Bottom Line: The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins.The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability.This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Molecular Biology, Miller School of Medicine, University of Miami , 1011 NW 15th Street, Miami, Florida 33136, United States.

ABSTRACT
Advancements in biotechnology have allowed for the preparation of designer proteins with a wide spectrum of unprecedented chemical and physical properties. A variety of chemical and genetic methods can be employed to tailor the protein's properties, including its stability and various functions. Herein, we demonstrate the production of semisynthetic glucose recognition proteins (GRPs) prepared by truncating galactose/glucose binding protein (GBP) of E. coli and expanding the genetic code via global incorporation of unnatural amino acids into the structure of GBP and its fragments. The unnatural amino acids 5,5,5-trifluoroleucine (FL) and 5-fluorotryptophan (FW) were chosen for incorporation into the proteins. The resulting semisynthetic GRPs exhibit enhanced thermal stability and increased detection range of glucose without compromising its binding ability. These modifications enabled the utilization of the protein for the detection of glucose within physiological concentrations (mM) and temperatures ranging from hypothermia to hyperthermia. This ability to endow proteins such as GBP with improved stability and properties is critical in designing the next generation of tailor-made biosensing proteins for continuous in vivo glucose monitoring.

Show MeSH
Related in: MedlinePlus