Recombinant human CD55 / DAF Protein, His tag, 100µg

Background
CD55, also known as DAF or decay­accelerating factor, is a member of the RCA (regulators of complement activation) family characterized by four to 30 SCRs (short consensus repeats) in their plasma-exposed regions. CD55 / DAF is a 70 kDa membrane protein that regulates the complement system on the cell surface. It prevents the assembly of the C3bBb complex (the C3-convertase of the alternative pathway) or accelerates the disassembly of preformed convertase, thus blocking the formation of the membrane attack complex. This glycoprotein is broadly distributed among hematopoietic and non-hematopoietic cells. It is a determinant for the Cromer blood group system. CD55 is known to bind CD97 via the first SCR. It also binds physiologically­generated C3 convertases with its second and third SCRs. Binding results in an accelerated “decay”, or dissociation of active C3 convertases, thus blocking the development of C’ attack complexes on nonforeign cells. Finally, viruses and bacteria are also known to utilize multiple SCR sites for infection.[1-5]

Source
Recombinant Human CD55 /DAF Protein (rhCD55), His Tag (CD5-H5225) is expressed from human 293 cells (HEK293). It contains AA Asp 35 - Ser 353 (Accession # NP_000565.1).
Predicted N-terminus: Asp 35

Molecular Characterization
This protein carries a polyhistidine tag at the C-terminus.
The protein has a calculated MW of 35.8 kDa. The protein migrates as 50-65 kDa under reducing (R) condition (SDS-PAGE) due to glycosylation.

Endotoxin
Less than 1.0 EU per μg by the LAL method.

Purity
>95% as determined by SDS-PAGE.

Formulation
Lyophilized from 0.22 μm filtered solution in PBS, pH7.4. Normally Trehalose is added as protectant before lyophilization.

Reconstitution
See Certificate of Analysis for details of reconstitution instruction and specific concentration.

Storage
For long term storage, the product should be stored at lyophilized state at -20°C or lower.
Please avoid repeated freeze-thaw cycles.
This product is stable after storage at:
-20^°C to -70^°C for 12 months in lyophilized state;
-70^°C for 3 months under sterile conditions after reconstitution.

Clinical and Translational Updates

(1) "Evolution of red blood cell membrane complement regulatory proteins and rheology in septic patients: An exploratory study"
Vanderelst, Rousseau, Selvais et al
Front Med (Lausanne) (2022) 9, 880657
(2) "He reshaped the forefront of xenotransplantation: Agustin Pasqual Dalmasso (1933-2021)"
Platt, Vercellotti
Xenotransplantation (2022)
(3) "Overexpression of Decay Accelerating Factor Mitigates Fibrotic Responses to Lung Injury"
Vittal, Fisher, Thompson et al
Am J Respir Cell Mol Biol (2022)
Showing 1-3 of 2441 papers.

Citations
"Distinct CD55 isoform synthesis and inhibition of complement-dependent cytolysis by hepatitis C virus"
Authors: Kwon YC, et al.
Journal: J Immunol 2016
Application: CDC assay