. Author manuscript; available in PMC: 2012 Oct 25.

Published in final edited form as: Biochemistry. 2011 Sep 27;50(42):9158–9166. doi: 10.1021/bi2013382

Table 2.

Competitive kinetic isotope effects for uridine phosphorolysis catalyzed by TcUP.

^L(V/K)_uridine Position	Remote Label	Type of ^L(V/K)_uridine	^L(V/K)_uridine
1′-³H	[5′-¹⁴C]uridine	α-Secondary	1.063 ± 0.002^a
1′-¹⁴C	[1′-³H]uridine	Primary	1.069 ± 0.004^b
5′-¹⁴C,1,3-¹⁵N	[1′-³H]uridine	Primary, β-Secondary	1.018 ± 0.004^b

Measured with [5′-¹⁴C]uridine as remote label, assuming ^δ-14(V/K) to be unity.

Corrected for [1′-³H]uridine as remote label according to the equation ^L(V/K) = ^L(V/K)_obs × ^α-T(V/K).