![Fig. 4. Appearance of free thiol groups on α1m after cleavage with erythrocyte membranes. / (A) A quantity of 3 μg free plasma–α1m (lane 1) was incubated with erythrocyte membranes and purified by affinity chromatography on a column with anti-α1m (lane 2). The samples were treated with [14C]IAA, separated by SDS-PAGE, stained, and analyzed by phosphoimaging. (B) A quantity of 10 μg IgA-α1m was either left untreated (lane 1), alkylated with cold IAA (lane 2), or alkylated with cold IAA and incubated with lysed erythrocytes (lane 3). The proteins were then incubated with [14C]IAA, separated by SDS-PAGE and stained, or analyzed by phosphoimaging. (C) The α1m-fragment of IgA-α1m was prepared by pepsin digestion. A quantity of 3 μg of the α1m-fragment was either left untreated (lane 1) or incubated with lysed erythrocytes (lane 2). The proteins were incubated with [14C]IAA, separated by SDS-PAGE and stained, or analyzed by autoradiography. All electrophoreses were performed in the presence of mercaptoethanol.](https://ash.silverchair-cdn.com/ash/content_public/journal/blood/99/6/10.1182_blood.v99.6.1894/6/h80622232004.jpeg?Expires=1735511698&Signature=yelWJR1ihrqC4IzbRk54RtJcmOxM4mp7EHqL2B31kN2D-yakZWKZt6Fg7zVqjRXusaB7FRStDHwRWkPMj5BBeq4hJOlbzQUBsEQcn9um8CzsNNCiOrt0JGbpingkWpsocCdvT0~~ReaHMdnMTkOPTN1xrcOz1hqGmU69oJKedw5Rb-6U1bzMQ9x8SRfkjGPZWlUf9So6MKvuToWvngD3HYe-kPrgry6qLbMYBNQZu76MFR3EDjcLtJWfRjGGFy83n7s1NTwFWPn-MtzZOYBMbAwZnriz0RBdsEFFdCxnLcMNc4iCSCx9Fps0EvpHgtGSSodV7C1f6aYAN5goCRbCNA__&Key-Pair-Id=APKAIE5G5CRDK6RD3PGA)
Appearance of free thiol groups on α1m after cleavage with erythrocyte membranes.
(A) A quantity of 3 μg free plasma–α1m (lane 1) was incubated with erythrocyte membranes and purified by affinity chromatography on a column with anti-α1m (lane 2). The samples were treated with [14C]IAA, separated by SDS-PAGE, stained, and analyzed by phosphoimaging. (B) A quantity of 10 μg IgA-α1m was either left untreated (lane 1), alkylated with cold IAA (lane 2), or alkylated with cold IAA and incubated with lysed erythrocytes (lane 3). The proteins were then incubated with [14C]IAA, separated by SDS-PAGE and stained, or analyzed by phosphoimaging. (C) The α1m-fragment of IgA-α1m was prepared by pepsin digestion. A quantity of 3 μg of the α1m-fragment was either left untreated (lane 1) or incubated with lysed erythrocytes (lane 2). The proteins were incubated with [14C]IAA, separated by SDS-PAGE and stained, or analyzed by autoradiography. All electrophoreses were performed in the presence of mercaptoethanol.
