Recombinant Human CL-K1/COLEC11 Protein, CF

Collectins constitute a family of C-type lectins that recognize molecular patterns expressed on pathogens. Members of this glycoprotein family contain an N-terminal domain, a collagen-like domain, a neck region, and a C-terminal carbohydrate recognition domain (CRD). Collectins are typically secreted molecules, although CL-P1 is membrane bound and CL-L1 is found in the cytoplasm (1 - 3). Collectin kidney 1 (CL-K1), also known as collectin subfamily member 11 (COLEC11), is a 37 kDa collectin that circulates in the blood (4, 5). Alternative splicing may generate multiple isoforms with deletions or substitutions in the N-terminal and collagen-like domains (6). CL-K1 is widely expressed, notably in renal proximal tubules, bronchial glands, and gastrointestinal mucosa (5). It associates into disulfide-linked oligomers and preferentially interacts with fucose residues in a calcium-dependent manner (4). Mature human CL-K1 shares 93% amino acid sequence identity with mouse and rat CL-K1. Within the CRD, human CL-K1 shares 55% aa sequence identity with CL-L1 and 26% - 33% aa sequence identity with collectins CL-P1, MBL, SP-A, and SP-D.