Preparation: Protein-A/G purified
Content: Available in 200 µL and 1 mL size.1 mg/mL +/- 15%. See Certificate of Analysis for details.
Solvent: 0.01 M phosphate buffer, pH 7.4, with 0.5 M NaCl and 15 mM sodium azide
Storage: 4-8ºC without exposure to light. No precautions necessary during handling.

C1s proenzyme is a 79.8 kDa glycoprotein produced primarily by hepatocytes (1) but also by other cells (2,3). The proenzyme is produced as a single-chain polypeptide of 688 aa. Upon activation the peptide is cleaved between R437 and I438 giving the activated enzyme consisting of two disulfide-linked chains, A chain (52.2 kDa) and B chain (27.7 kDa). The Ca-dependent catalytic subunit of the C1 complex (C1q, C1r, C1s) comprises of two C1s and two C1r molecules and this serine protease tetramer is responsible for the initial steps in the classical complement pathway, cleavage of C4 and C2 (1,4,5).

Human plasma C1s Proenzyme adsorbed onto aluminum hydroxide gel

ABS 002-49 is specific for C1s proenzyme and activated free C1s and C1s in complex with C1 inhibitor.

Epitope differs from that of ABS 002-09

ABS 002-49 reacts in ELISA when tested with activated C1s enzyme directly coated onto the microtiter well or in sandwich ELISA in combination with a polyclonal antibody in coat.