Abstract
We describe the characterization of the antigen (s) in human pancreatic β-cell line (JHPI-1) recognized by islet cell surface antibodies that have been found in the serum of insulin-dependent diabetes mellitus (IDDM). Briefly, NP-40 lysates of JHPI-1 cells were analyzed by SDS-PAGE on 7.5-10% uniform slab gels in a discontinuous buffer system of Laemmli. The proteins in the slabgel were electrophoretically transferred onto nitrocellulose membranes. The transferred nitrocellulose membranes were incubated with islet cell surface antibodies or normal healthy control serum as first antibodies, and stained using the Avidin-Biotin method. As a result, six bands, 120 K, 80 K, 64 K, 42 K, 34 K and 27 K proteins, were tentatively identified. On the other hand, control serum did not provide any ricognizable proteins. It is concluded that islet cell surface antibodies recognize a protein with Mr 64, 000 expressed in JHPI-1 cells as previously reported in human islet cells.
