Table 1.

Labeling times t1–t5 used for hydrogen exchange at different temperatures

	Labeling time (sec)a
Temperature	t1	t2	t3	t4	t5
37°C	28	56	112	224	448
42°C	18	36	72	144	288
47°C	12	24	48	96	192
52°C	8	16	32	64	128
57°C	5	10	20	40	80

^a The times were chosen to offset the temperature dependence of the intrinsic rates of hydrogen exchange.