The detection of cross-reacting material for alpha-antitrypsin in liver extracts by acid-starch electrophoresis.
Purified extracts of alpha-antitrypsin cross-reacting material (CRM) from liver of patients with MM, ZZ, and MZ phenotypes were studied by acid-starch electrophoresis and crossed immunoelectrophoresis. It is believed that CRM-M from liver is derived primarily from postmortem digested serum antitrypsin, whereas CRM-Z is a product of postmortem digested antitrypsin from hepatocytes. All extracts produced small bands of antitrypsin on the cathodal side of the gel: A single M band migrated faster than the single Z band, whereas CRM from an MZ heterozygote produced a combination of 2 mobile bands. The CRM-Z (from a ZZ phenotype) did not migrate toward the anode, in contrast to the presence of a broad plateau of antitrypsin protein with CRM-M (from an MM phenotype) or CRM-MZ. Thus, most of the CRM-Z protein could not be accounted for on routine acid-starch electrophoresis. However, an anodal peak could be seen on starch gels with CRM-Z at less acidic pH, suggesting that the anodal-migrating CRM-Z protein is denatured and loses antigenicity at lower pH.
D003429:Cross Reactions; D004592:Electrophoresis, Starch Gel; D006579:Heterozygote; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007122:Immunoelectrophoresis; D008099:Liver / Q000276:immunology*; D010641:Phenotype; D011489:Protein Denaturation; D000515:alpha 1-Antitrypsin / Q000276:immunology*; D019896:alpha 1-Antitrypsin Deficiency
D000515:alpha 1-Antitrypsin