Original Paper Figure 1. Prelamin A process- ing and prelamin A specific sequences. (A) The scheme shows the subsequent prelamin A processing steps (1 to 4) and the prelamin A processing intermediates. The names used in this study for each prelamin A form are reported on the right. The pro- tein residues targeted by anti- prelamin A antibodies 1188-1 (boxed area in preLA-CSIM) and 1188-2 (boxed area in preLA-farnesyl-C) are high- lighted. Reported in (B) and (C) are the sequences of the prelamin A-specific peptides used to produce antibody 1188-1 and 1188-2, respec- tively. The mass spectrum of each peptide is shown in (D) (peptide 1188-1) and (E) (pep- tide 1188-2). Aminoacid sym- bols in (A), (B) and (C) are in red characters. Figure 2. Antibodies 1188-1 and 1188-2 react with prelamin A, but not mature lamin A. (A) ELISA was per- formed on 1188-1 peptide to evaluate the affinity of anti- body 1188-1. The binding activity of 1188-2 antibody is shown as a control. (B) ELISA was performed on 1188-2 pep- tide to evaluate the affinity of antibody 1188-2. The binding activity of 1188-1 antibody is shown as a control. (C) Binding affinity of antibodies 1188-1 and 1188-2 for recom- binant full-length prelamin A or mature lamin A (D) was evaluated by ELISA. Antibody 1188-1 bound full-length prelamin A but not mature lamin A. Antibody 1188-2 did not bind neither full-length prelamin A, nor mature lamin A. 45