Skip to main content

Table 1 Effect of protonation on the barrier ΔEǂ of the concurrent reaction [a]

From: Effects of protonation on the hydrolysis of triphosphate in vacuum and the implications for catalysis by nucleotide hydrolyzing enzymes

nP = 0 nP = 1 nP = 2 nP = 3
44.0 α: [b] αγ: 34.5 αβγ: 39.9
  β: [b] αβ: [b]   
  γ: 32.4 βγ: 35.1   
  1. [a] ΔEǂ is the energy (AM1/d in kcal mol−1) difference between the optimized reactant and the rate limiting transition state (saddle point). nP is the number of protons on the triphosphate (α, β and γ indicate which phosphate group is protonated). [b] Various searches for a concurrent reaction failed (hydrolysis always proceeded through a sequential mechanism, see Table 2)