K. Karska et al., CALRETICULIN - THE POTENTIAL AUTOANTIGEN IN CELIAC-DISEASE, Biochemical and biophysical research communications, 209(2), 1995, pp. 597-605
Monoclonal antibodies to gliadin were recently found to cross-react wi
th epitopes on rat enterocytes. Two molecules of mel. mass 62 and 66 k
Da were isolated from enterocyte lysates by affinity chromatography us
ing antigliadin monoclonal antibodies. The N-terminal amino acid seque
nce of the 62-kDa protein was determined to be XXXIYFKEQFLD. This amin
o acid sequence corresponds to amino acid sequence of rat calreticulin
. The presence of calreticulin in enterocyte lysates was further confi
rmed using anticalreticulin serum. Anticalreticulin serum was also use
d to investigate the reactivity of isolated rat calreticulin. To analy
ze whether gliadin and calreticulin share similar epitopes recognized
by anticalreticulin antibodies, synthetic dodecapeptides derived from
the amino acid sequence of a gliadin were used in competitive ELISA as
say. Two gliadin peptides, QEQVPLVQQQQF and YQLLQELCCQHL, were found t
o inhibit the binding of rabbit anti-rat calreticulin sera to rat calr
eticulin. The significant correlation was detected between IgA antical
reticulin and antigliadin antibodies (r = 0.827; P < 0,001) in celiac
patients. (C) 1995 Academic Press, Inc.