A. Mcalpine

Publications (3)4.06 Total impact

• Source

  Available from: gla.ac.uk

  Article: Calorimetric studies of the energetics of protein-DNA interactions in the E. coli methionine repressor (MetJ) system.

  A Cooper, A McAlpine, P G Stockley
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  ABSTRACT: Calorimetric measurements of binding of a specific DNA fragment and S-adenosyl methionine (SAM) co-repressor molecules to the E. coli methionine repressor (MetJ) show significant differences in the energetics of binary and ternary protein-DNA complexes. Formation of the MetJ:SAM:DNA ternary complex is significantly more exothermic (delta H congruent to -99 kJ.mol-1) than either MetJ:DNA or MetJ:SAM binary complexes alone (delta H congruent to -10 kJ.mol-1 each). The protein is also significantly more stable to unfolding (delta Tm congruent to 5.4 degrees C) when bound to DNA. These observations suggest that binding of SAM to the protein-DNA complex leads to a significant reduction in dynamic flexibility of the ternary complex, with considerable entropy-enthalpy compensation, not necessarily involving any overall conformational change.
  FEBS Letters 08/1994; 348(1):41-5. · 3.54 Impact Factor
• Article: Structure of the thromboxane receptor antagonist EP 092.

  A McAlpine, L Sawyer, P Taylor, A J Blake
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  ABSTRACT: 7-(3-[1-(4-Phenylthiosemicarbazono)ethyl]-bicyclo[2.2.1]hept-2- yl)-5-heptenoic acid, C23H31N3-O2S, Mr = 413.7, monoclinic, P2(1)/a, a = 12.9650 (7), b = 11.2081 (6), c = 16.8941 (12) A, beta = 110.452 (5) degrees, V = 2300.2 A3, Z = 4, Dx = 1.194 g cm-3, Mo K alpha, lambda = 0.71073 A, mu = 1.55 cm-1, F(000) = 888, T = 298 K. Final R = 0.0472 with 2778 independent data. EP 092 is a thromboxane receptor antagonist akin to many other analogues of the thromboxane A2 [Wilson & Jones (1985). Adv. Prostaglandin Thromboxane Leukotriene Res. 14, 393-425].
  Acta Crystallographica Section C Crystal Structure Communications 04/1990; 46 ( Pt 3):447-50. · 0.52 Impact Factor
• Article: Calorimetric Studies of the Energetics of Protein-Dna Interactions in the Escherichia-Coli Methionine Repressor (Metj) System

  A Cooper, A. Mcalpine, P G Stockley
  [show abstract] [hide abstract]
  ABSTRACT: Calorimetric measurements of binding of a specific DNA fragment and S-adenosyl methionine (SAM) co-repressor molecules to the E. coli methionine repressor (MetJ) show significant differences in the energetics of binary and ternary protein-DNA complexes. Formation of the MetJ:SAM:DNA ternary complex is significantly more exothermic (Delta H similar or equal to -99 kJ.mol(-1)) than either MetJ:DNA or MetJ:SAM binary complexes alone (Delta H similar or equal to -10 kJ.mol(-1) each). The protein is also significantly more stable to unfolding (Delta T-m similar or equal to 5.4 degrees C) when bound to DNA. These observations suggest that binding of SAM to the protein-DNA complex leads to a significant reduction in dynamic flexibility of the ternary complex, with considerable entropy-enthalpy compensation, not necessarily involving any overall conformational change.