CD81, also known as CD81 antigen isoform 1, belongs to the tetraspanin family. It interacts directly with immunoglobulin superfamily member 8 (IGSF8, CD316) and CD36. In B cells, it is part of a complex with CD21, CD19 and Leu13. This complex reduces the threshold for B cell activation through B cell receptors by linking Ag specific recognition and CD21 mediator recognition. On T cells it associates with CD4 and CD8 and provides a costimulatory signal with CD3. Source: Recombinant protein corresponding to aa113-201 from human CD81, fused to hIgG-His-Tag at C-terminal, expressed in insect cell. Molecular Weight: ~37kD (331aa), 40-57kD (SDS-PAGE under reducing conditions) Endotoxin: <1EU/1ug (determined by LAL method) AA Sequence: ADPFVNKDQI AKDVKQFYDQ ALQQAVVDDD ANNAKAVVKT FHETLDCCGS STLTALTTSV LKNNLCPSGS NIISNLFKED CHQKIDDLFS GKLEPKSCDK THTCPPCPAP ELLGGPSVFL FPPKPKDTLM ISRTPEVTCV VVDVSHEDPE VKFNWYVDGV EVHNAKTKPR EEQYNSTYRV VSVLTVLHQD WLNGKEYKCK VSNKALPAPI EKTISKAKGQ PREPQVYTLP PSRDELTKNQ VSLTCLVKGF YPSDIAVEWE SNGQPENNYK TTPPVLDSDG SFFLYSKLTV DKSRWQQGNV FSCSVMHEAL HNHYTQKSLS LSPGKHHHHH H Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing. Store at -20C. Aliquots are stable for 12 months after receipt. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap.
