Integrin alphaV, beta8, Recombinant, Human

Artikelname:	Integrin alphaV, beta8, Recombinant, Human
Artikelnummer:	USB-I7661-37X8
Hersteller Artikelnummer:	I7661-37X8
Alternativnummer:	USB-I7661-37X8-50
Hersteller:	US Biological
Kategorie:	Molekularbiologie

Integrin alphavbeta8 is one of five alphav integrins and the only known beta8 integrin. 1-3 The non-covalent heterodimer of 170 kD alphav and ~90 kD beta8 integrin type I transmembrane glycoprotein subunits is expressed in yolk sac, placenta, brain perivascular astrocytes, Schwann cells, renal glomerular mesangial cells and pulmonary epithelial cells. 3-7 Unlike other alphav integrins, alphavbeta8 does not appear to assume different activation states, and the cytoplasmic tail does not connect to the cytoskeleton. 3, 8 It binds ligands containing an RGD motif, including vitronectin, fibrin and the latency associated peptide (LAP) of the latent TGF-beta complex. 7-12 High affinity binding of alphavbeta8 to LAP allows proteolytic cleavage by MT1-MMP, which releases active TGF-beta. This mechanism differs from that of alphavbeta6, the other alphav integrin which can activate TGF-beta from latency through non-proteolytic mechanisms. 13 Downstream effects of TGF-beta activation include control of cell growth and associated vascularization. 10-13 Deletion of either alphav or beta8 reveals that alphavbeta8 is required for vascular morphogenesis in the embryonic brain and yolk sac. 4, 14, 15 The 962 aa human alphav extracellular domain (ECD) shares 92-95% aa sequence identity with mouse, rat and cow alphav, while the 642 aa human beta8 ECD shares 92%, 92%, 89%, 87% and 87% aa identity with cow, dog, rabbit, mouse and rat beta8, respectively. The beta8 ECD of beta8 shows low (~35%) aa identity with other integrin beta subunits, and the cytoplasmic tail is unlike any other integrin. The alphav ECD contains an N-terminal beta- propeller structure, followed by domains termed thigh, calf-1 and calf-2. 1 The beta8 ECD contains a vWFA domain, which interacts with the alphavbeta-propeller to form a binding domain. Each subunit has a transmembrane sequence and a short cytoplasmic tail. Source: Human CD33 Signal Peptide (Met 1-Ala 16), Human Integrin alphaV (Phe 31-Val 992) acidic tail, Human CD33 Signal Peptide (Met 1-Ala 16), Human Integrin beta8 (Glu 43-Arg 684) basic tail, DNA sequences encoding the extracellular domain of human Integrin alphaV (Phe 31-Val 992, Accession P06756) (Suzuki, S. et al., 1987, J. Biol. Chem. 262:14080-085) with an acid tail at the C-terminus and the extracellular domain of human Integrin beta8 (Glu 43-Arg 684, Accession P26012) (Moyle, M. et al., 1991, J. Biol. Chem 266:19650-658) with a basic tail at the C-terminus were cloned downstream of the human CD33 signal peptide and co-expressed in CHO cells. Molecular Mass: Based on N-terminal sequencing, the recombinant human Integrin alphaV subunit starts at Phe 31 and has a calculated molecular mass of approximately 111 kD. The beta8 subunit starts at Glu 43 and has a calculated molecular mass of approximately 75.3 kD. As a result of glycosylation, the recombinant proteins migrate as approximately 130-155 and 85-100 kD protein bands in SDS-PAGE under reducing conditions. Endotoxin Level: < 1.0 EU per 1 µg of the protein as determined by the LAL method. Activity: Measured by its ability to bind rhLap. When rhIntegrin alphaVbeta8 is coated at 0.1ug/ml, rhLap binds with an apparent KD < 0.5 nM. Reconstitution: It is recommended that sterile PBS be added to the vial to prepare a working stock solution of no less than 100ug/ml. The carrier-free protein should be used immediately upon reconstitution to avoid losses in activity due to non-specific binding to the inside surface of the vial. For long term storage as a dilute solution, a carrier protein (e.g. 0.1% HSA or BSA) should be added to the vial. Storage and Stability: Lyophilized samples are stable for up to twelve months at -20C. Upon reconstitution, this protein, in the presence of a carrier protein, can be stored under sterile conditions at 2-8 C for one month or at -20C in a manual defrost freezer for three months without detectable loss of activity. Avoid repeated freeze-thaw cycles.

NCBI:	002201
UniProt:	P26012
Reinheit:	90%, as determined by SDS-PAGE and visualized by silver stain.
Formulierung:	Supplied as a lyophilized powder in 50mM Tris, pH 7.4, 150mM NaCl and 2mM MgCl2.