The 56 MAbs submitted to the ISOBM TD-4 Workshop were analysed by ELIS
A assay for reactivity against synthetic MUC1 mucin protein core-relat
ed peptides. With peptides comprising 5, 7 and 20 amino acids, 4/56 (7
.1%), 33/56 (58.9%) and 51/56 (91.1%) of antibodies showed positive re
activity, respectively, Peptides with 60, 80, 100 and 120 amino acids
showed 50/56 (98.2%), 54/56 (96.4%), 53/56 (94.6%) and 47/56 (83.9%) a
ntibodies with positive reactivity, respectively. The reactivity of ea
ch MAb with synthetic peptides was classified into 3 groups. In group
A(15 MAbs), the reactivity increased depending on the peptides in leng
th and was maximal with 20-, 60-, 80-, 100- and 120-mer peptides. In g
roup B (24 MAbs), most antibodies showed very weak binding affinity to
peptides with a small increase in reactivity with the 100- and 120-me
r peptides. In group C (17 MAbs), the reactivity showed strong binding
affinity with the 20-mer peptide followed by a reduced uneven pattern
of reactivity with the 60-, 80-, 100- and 120-mer peptides. These res
ults show that the binding affinity of MAbs against synthetic peptides
does not depend on the recognition of antibodies to the epitopes of c
ore protein.