Bcakground

Insulin-like Growth Factor II (IGF-II) is a potent mitogenic growth factor. However, unlike IGF-I which has important postnatal roles, the growth -promoting function of IGF-II is limited to embryonic development. Insulin-like growth factor I (also known as somatomedin C and somatomedin A) and insulin-like growth factor II (multiplication stimulating activity or MSA) belong to the family of insulin-like growth factors that are structurally homologous to proinsulin. Mature IGF-I and IGF-II share approximately 70% sequence identity. Both IGF-I and IGF-II are expressed in many tissues and cell types and may have autocrine, paracrine and endocrine functions. Mature IGF-I and IGF-II are highly conserved (100% identity between human, bovine and porcine proteins) and exhibit cross-species activity. Two specific cell surface receptors that bind IGF-I and IGF-II have been identified. The type I IGF receptor that participates in IGF signaling is structurally related to the insulin receptor. It is a disulfide-linked heterotetrameric transmembrane glycoprotein with an intracellular tyrosine kinase domain. Type I IGF receptor binds IGF-I with higher affinity than IGF-II. The type II IGF receptor which binds IGF-II with much higher affinity than IGF-I is also the cation -independent mannose 6-phosphate receptor. At the present time, it is not known if the type II IGF receptor participates in the IGF signaling pathway. An additional unknown receptor which mediates IGF-II signaling has also been proposed. Circulating IGFs exist in complexes bound to IGF binding proteins. Currently, at least six high affinity binding proteins have been identified.

Reference

1. Harvey MB, et al. (1991) Development. 111(4): 1057-60.

2. Peters G, et al. (2003) Virchows Arch. 443(2): 139-45.

3. Burrow S, et al. (1998) J Surg Oncol. 69(1): 21-7.

Specifications

Synonyms	C11orf43; chromosome 11 open reading frame 43; FLJ22066; GRDF; IGF2; IGF-2; IGFII; IGF-I
Accession #	P01344.1
Source	Human embryonic kidney cell, HEK293-derived human IGF-II/IGF2 protein
Source	Ala25-Glu91
Predicted Moleucular weight	7.5 kDa

Components and Storage

Formulation	Solution protein
	Dissolved in sterile PBS buffer
	This solution can be diluted into other aqueous buffers. Centrifuge the vial prior to opening
Storage and Stability	Avoid repeated freeze-thaw cycles.
	It is recommended that the protein be aliquoted for optimal storage
	12 months from date of receipt, -20 to -70 °C as supplied.
Shipping	Shipping with dry ice

Quality

Purity	> 95%, determined by SDS-PAGE
Endotoxin Level	<0.010 EU per 1 ug of the protein by the LAL method
Activity	Measured in a serum-free cell proliferation assay using MCF-7 human breast cancer cells.
Activity	The EC50 for this effect is 0.6-2 ng/mL.

SDS-PAGE

Gel filtration

Bioactivity

Documents

Human IGF2