Table 3.

ADA Activity of Human–Mouse Hybrids Expressed in E. coli SØ3834

ADA cDNA	ADA activity(mean ± SD)	Wild-typehuman ADA
	μmol/min per mg protein	%
Human wt	3.3 ± 0.7	100.0
Mouse wt	12.4 ± 1.3	375.7
M1–81/H82–363	13.5 ± 2.2	409.0
H1–81/M82–125/H126–363	4.3 ± 0.4	130.3
H1–125/M126–143/H144–363 (“m126–143”)	1.2 ± 0.1	36.3
H1–143/M144–247/H248–363	2.9 ± 0.3	87.8
H1–247/M248–352	2.0 ± 0.2	60.6
H1–81/M82–352	1.8 ± 0.7	54.5
M1–247/H248–363	12.3 ± 3.8	372.7
M1–125/H126–143/M144–352 (“h126–143”)	13.1 ± 3.6	396.9

wt, wild-type; H, human; M, mouse.