Table 1.

Conversion of inactive rhGIF to bioactive derivatives by treatment with a SH reagent

Reagent	Concentration, mM	CM-5PM fraction	Bioactivity,* ng/ml
None	0	—	>1000
Iodoacetic acid	10	Peak 1	62
		Peak 2	150
		Peak 3	250
		Peak 4	>1000
EMTS	0.05	—	10
	0.25	—	5
	0.25	+†	2
DTNB	0.10	—	10
	0.25	—	8
	0.25	+‡	5

The − and + indicate before and after fractionation, respectively, on a CM-5PM column. 

^*Minimum concentration of GIF peptide required for the detection of bioactivity. 

^†Peak 2 fraction in Fig. 4A. 

^‡The major protein peak, recovered between 26 and 29 min in Fig. 4B.