AnaSpec has introduced two keratin antibodies that recognise both the intact and caspase digested N-terminal of K18 and K19 at Asp237
These antibodies are useful tools for studying keratin dynamics in mice undergoing hepatocyte apoptosis, patients with cirrhosis, and also in apoptotic cells of various epithelial human tumors in a non-invasive manner.
Intermediate filaments (IFs), together with actin microfilaments and tubulin microtubules, comprise the three major cytoskeletal networks that are found in most eukaryotic cells.
Keratins, which are the largest IF protein subgroup, can be divided into the acidic type I (K9-K20) and basic type II (K1-K8) Keratins.
Typically, epithelial cells express at least one of each type, and the proteins exist in the cells as noncovalent obligate heteropolymers.
Keratin networks are highly dynamic and reorganized during cell differentiation, mitosis and apoptosis, and also play important cytoprotective and structural support roles for the cell.
During apoptosis, the epithelial keratins 18 and 19 undergo caspase-mediated proteolysis, leading to the disassembly of the nuclear envelope and cytoplasmic IF networks.
K18 and K19 undergo caspase-cleavage at the conserved Asp237 in their rod domains.
In contrast to other type I keratins, K18 is unique in that it includes another caspase-cleavage site at Asp396 of the carboxy-terminal domain.
Rabbit anti-human Keratin-18 (Asp237) or anti-human Keratin-19 (Asp237) polyclonal antibodies were raised against a synthetic peptide corresponding to an internal sequence surrounding amino acid 237 (GLTVEVD) of human Keratin-18 or amino acid 237 (QVSVEVD) of human Keratin-19, respectively.
Anti-Keratin 18 reacts to both cleaved keratin-18 (Asp237) (29 kDa) and intact Keratin-18 (49 kDa) proteins from anisomycin-treated human colonic carcinoma HT29 cell lysate and Fas antibody-induced mouse liver lysate (see figure below).
This antibody also reacts to cleaved Keratin-19 (Asp237) (29 kDa).6 Anti-Keratin 19 reacts to both cleaved keratin-19 (Asp237) (29 kDa) and intact Keratin-19 (45 kDa) proteins from anisomycin-treated human colonic carcinoma HT29 cell lysate.
This antibody also reacts to cleaved Keratin-18 (Asp237) (29 kDa).6 Both antibodies are human, mouse, and monkey reactive.
