Insulin-like growth factor I, also known as somatomedin C, is the dominant effector of growth hormone and is structurally homologous to proinsulin. Human IGF-I is synthesized as two precursor isoforms with N- and alternate C- terminal propeptides (1). These isoforms are differentially expressed by various tissues (1). The 7.6 kDa mature IGF-I is identical between isoforms and is generated by proteolytic removal of the N- and C- terminal regions. Mature human IGF-I shares 94% and 96% aa sequence identity with mouse and rat IGF-I, respectively (2), and exhibits cross-species activity. It shares 64% aa sequence identity with mature human IGF-II. Circulating IGF-I is produced by hepatocytes, while local IGF-I is produced by many other tissues in which it has paracrine effects.
Aliases- Somatomedin, Insulin-like growth factor I, IGF-I, Igf1
- Recombinant Rat Insulin-Like Growth Factor (IGF1)
Formulation- Recombinant Rat IGF1 was lyophilized from a 0.2 µm filtered PBS solution, pH 7.4.
Endotoxin Level- <1.0 EU/µg of recombinant protein as determined by the LAL method.
Storage Condition- The lyophilized protein is stable for at least one year from date of receipt at -70°C. Upon reconstitution, this cytokine can be stored in working aliquots at +2° to +8°C for one month, or at -20°C for six months, with a carrier protein without detectable loss of activity. Avoid repeated freeze/thaw cycles.