The RGD sequence generally exists in the extracellular matrix proteins and can be recognized by many integrin proteins. The binding ability of immobilized biotinylated cyclic hexapeptide [cyclo(-Arg-Gly-Asp-D-Phe-Lys-...The RGD sequence generally exists in the extracellular matrix proteins and can be recognized by many integrin proteins. The binding ability of immobilized biotinylated cyclic hexapeptide [cyclo(-Arg-Gly-Asp-D-Phe-Lys-Gly-)] containing RGD to integrin ααbβ3 was tested by the methods of ELISA and SPR. Results showed that a spacer of 1.48-2.2 nm between the peptide and the biotin residue was long enough to send the RGD sequence into the binding center embedded within αⅡbβ3, and the equilibrium dissociation constant was 1.1μm. The work provides an ideal model system for the research of cell adhesion on solid surfaces.展开更多
characterize the activation of platelet integrin αⅡbβ3 induced by two anti human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action Method...characterize the activation of platelet integrin αⅡbβ3 induced by two anti human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action Methods Using 125 I labeled human fibrinogen (Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured Results HI117 and SJ9A4 (10?μg/ml and 20?μg/ml) induced specific Fg binding to human platelets, suggesting that the two mAbs evoked activation of platelet integrin αⅡbβ3 Further study indicated that HI117 and SJ9A4 induced integrin αⅡbβ3 activation independent of platelet Fc receptors, and that HI117 and SJ9A4 induced integrin αⅡbβ3 activation was inhibited by pretreatment of platelets with sphingosine, aspirin, apyrase, and/or PGI 2 Conclusions Anti platelet tetraspanin (CD9) mAbs, HI117 and SJ9A4, can induce platelet integrin αⅡbβ3 activation independent of Fc receptors Three signaling pathways, namely thromboxane, secreted ADP, and cAMP pathways, may be involved in the process, with protein kinase C activation presumably being the common step of the three pathways展开更多
文摘The RGD sequence generally exists in the extracellular matrix proteins and can be recognized by many integrin proteins. The binding ability of immobilized biotinylated cyclic hexapeptide [cyclo(-Arg-Gly-Asp-D-Phe-Lys-Gly-)] containing RGD to integrin ααbβ3 was tested by the methods of ELISA and SPR. Results showed that a spacer of 1.48-2.2 nm between the peptide and the biotin residue was long enough to send the RGD sequence into the binding center embedded within αⅡbβ3, and the equilibrium dissociation constant was 1.1μm. The work provides an ideal model system for the research of cell adhesion on solid surfaces.
基金grantfromtheNationalNaturalScienceFoundationofChina (No 39470 172 )
文摘characterize the activation of platelet integrin αⅡbβ3 induced by two anti human platelet tetraspanin monoclonal antibodies (mAbs), HI117 and SJ9A4, and investigate their potential mechanism of action Methods Using 125 I labeled human fibrinogen (Fg), specific Fg binding to human platelets induced by HI117 and SJ9A4 was measured Results HI117 and SJ9A4 (10?μg/ml and 20?μg/ml) induced specific Fg binding to human platelets, suggesting that the two mAbs evoked activation of platelet integrin αⅡbβ3 Further study indicated that HI117 and SJ9A4 induced integrin αⅡbβ3 activation independent of platelet Fc receptors, and that HI117 and SJ9A4 induced integrin αⅡbβ3 activation was inhibited by pretreatment of platelets with sphingosine, aspirin, apyrase, and/or PGI 2 Conclusions Anti platelet tetraspanin (CD9) mAbs, HI117 and SJ9A4, can induce platelet integrin αⅡbβ3 activation independent of Fc receptors Three signaling pathways, namely thromboxane, secreted ADP, and cAMP pathways, may be involved in the process, with protein kinase C activation presumably being the common step of the three pathways
