Abstract
Human granulocyte elatase has ample opportunity to interact with immunoglobulins at both the intracellular and extracellular level. Thus, the susceptibility of human IgM to proteolysis by this enzyme was investigated. Treatment of monoclonal IgM with elastase in the presence of 2 m M cysteine for 18 hr at 37°C resulted in the formation of a major fragment (Frag. A) and small peptides. Fragment A had an approximate mol. wt of 50,000 as determined by gel filtration. Reduction and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of Frag. A revealed 2 bands having mol. wt of 23,000 and 30,000, respectively. Ouchterlony analysis showed Frag. A to contain light (K) chain and a portion of the heavy (μ) chain. Fragment A appeared to be antigenically identical with Fab produced by trypsin or papain digestion of IgM but completely different from Fc5μ produced by trypsin digestion of IgM. Fc5μ was digested to small peptides by the enzyme. These findings show that human PMN elastase can specifically degrade IgM in vitro, producing an Fab-like fragment and small peptides.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.