Figure 3.

Plasma from null ALS mice is unable to form 150-kDa complexes. Plasma from 10-week-old wild-type (+/+, lanes 1 and 2), heterozygous (+/−, lanes 3 and 4), and null (−/−, lanes 5 and 6) ALS mice were incubated overnight with [¹²⁵I]IGF-I in the presence of IGFBP-3. After crosslinking with disuccinimidyl suberate, complexes were separated by reducing SDS/PAGE. IGF-I-containing complexes are identified on the left, and positions of the molecular mass standards (in kilodaltons) are given on the right.