Publications by authors named "Audrey E Tolbert"

Hypertension remains a leading cause of cardiovascular and kidney diseases. Failure to control blood pressure with ≥ 3 medications or control requiring ≥ 4 medications is classified as resistant hypertension (rHTN) and new therapies are needed to reduce the resulting increased risk of morbidity and mortality. Here, we report genetic evidence that relaxin family peptide receptor 2 (RXFP2) is associated with rHTN in men, but not in women.

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Article Synopsis
  • Carbonic Anhydrases (CAs) are attractive targets for protein design due to their simple active site and fast reaction rates, with Zn(II) and Co(II) being common metal substitutions for studying their properties.
  • A new cobalt-substituted protein, [Co(II)(HO/OH)](TRIL2WL23H), exhibits behavior similar to human CAs, showing increasing catalytic activity as pH rises, surpassing the efficiency of its zinc counterpart above pH 10.
  • X-ray absorption and UV-vis spectroscopy reveal a transition from an octahedral to a 5-coordinate structure at higher pH, indicating this structural change correlates with catalytic efficiency, suggesting that the difficult ester hydrolysis is the rate
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While many life-critical reactions would be infeasibly slow without metal cofactors, a detailed understanding of how protein structure can influence catalytic activity remains elusive. Using de novo designed three-stranded coiled coils (TRI and Grand peptides formed using a heptad repeat approach), we examine how the insertion of a three residue discontinuity, known as a stammer insert, directly adjacent to a (His) metal binding site alters catalytic activity. The stammer, which locally alters the twist of the helix, significantly increases copper-catalyzed nitrite reductase activity (CuNiR).

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Three-stranded coiled coils are peptide structures constructed from amphipathic heptad repeats. Here we show that it is possible to form pure heterotrimeric three-stranded coiled coils by combining three distinct characteristics: (1) a cysteine sulfur layer for metal coordination, (2) a thiophilic, trigonal pyramidal metalloid (Pb(II)) that binds to these sulfurs and (3) an adjacent layer of reduced steric bulk generating a cavity where water can hydrogen bond to the cysteine sulfur atoms. Cysteine substitution in an a site yields Pb(II)AB heterotrimers, while d sites provide pure Pb(II)CD or Pb(II)CD scaffolds.

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Superoxide dismutases (SODs) are highly efficient enzymes for superoxide dismutation and the first line of defense against oxidative stress. These metalloproteins contain a redox-active metal ion in their active site (Mn, Cu, Fe, Ni) with a tightly controlled reduction potential found in a close range around the optimal value of 0.36 V versus the normal hydrogen electrode (NHE).

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