C1s Protein (His Tag)

Complement Component 1, S Subcomponent Protein Datasheet

C1s Protein Product Information

• C1s Synonym: C1s, FLJ44757
• Protein Construction: A DNA sequence encoding the recombinant human complement componentC1s (NP_001725.1) ( Met 1- Asp 688 ) was expressed with a C-terminal polyhistidine tag.
• Source: Human
• Expression Host: Human Cells

C1s Protein QC Testing

• Purity: > 97%, as determined by SDS-PAGE and SEC-HPLC Analysis
• Endotoxin: < 1.0 EU per 1μg of the protein as determined by the LAL method.
• Stability: Samples are stable for up to twelve months from date of receipt at -70℃
• Predicted N terminal: Glu 16
• Molecular Mass: The recombinant human C1s protease consists of 684 amino acids and has a predicted molecular mass of 76.3 kDa. As a result of glycosylation, rhC1s migrates as an approximately 95 kDa band in SDS-PAGE under reducing conditions.
• Formulation: Lyophilized from sterile PBS, pH7.5
• SDS-PAGE:

C1s Protein Usage Guide

• Storage: Store it under sterile conditions at -70℃. It is recommended that the protein be aliquoted for optimal storage and usage. Avoid repeated freeze-thaw cycles.
• Reconstitution: A hardcopy of COA with reconstitution instruction is sent along with the products. Please refer to it for detailed information.

C1s Protein Description

Complement is an integral component of the adaptive and innate immune systems and represents one of the major effector systems for the immune responses. The classical complement pathway is triggered by C1, a complex composed of the binding protein C1q and two proenzymes, C1r and C1s. Upon binding of IgG to the head of C1q, C1r undergoes autoactivation and in turn cleaves and activates C1s. As a highly specific serine protease, C1s executes the catalytic function of the C1 complex: the cleavage of C4 and C2, and thus instigates a sequence of activation steps of other components of the complement system, culminating in the formation of the membrane attack complex which induces cell lysis. The single-chain proenzyme C1s is processed into the active form of disulfide-linked two chains: the A chain contains multiple domains in the order of CUB1-EGF-CUB2-CCP1 -CCP2-Activation Peptide, while the B chain contains the serine protease catalytic domain. The only other protein known to interact with C1s physiologically is SerpinC1, an inhibitor of serine protease, which inhibits C1s activity and thus plays a regulatory role in controlling the function of C1s enzyme.

References

1. Illy, C. et al., 1991. Biochemistry. 30: 7135-7141.
2. Kusumoto, H. et al., 1988, Proc. Natl. Acad. Sci. USA 85:7307 - 7311.
3. Kerr, F.K. et al., 2005, J .Biol. Chem. 280: 39510-39514.
4. Busby Jr, W. H. et al., 2000, J. Biol. Chem. 275:37638-37644.
5. Gal, P. et al., 2002, Immunobiology. 205: 383-394.