4676
B I O C H E M I ST R Y
JEMMERSOK ET
AL.
Six Related Protein Products from a Single Patient with Multiple Myeloma? Ronald Jemmerson,*Barbara Kaplan, M. Drue Denton, Per Anderas, Byron Anderson, and E. Margoliash*
ABSTRACT: Six related myeloma protein materials were isolated from the serum and urine of a patient with multiple myeloma. These proteins were identified as an immunoglobulin G (IgG), a half-IgG, an aggregated IgG, an antigen-binding fragment (Fab), and two K light-chain variable-region (V,) dimers differing from each other by two arginyl residues at the carboxyl terminus. All six proteins had identical amino- terminal K-chain sequences. Heavy-chain components had blocked amino termini and thus were not sequenced. The IgG, aggregated IgG, and half-IgG had the same amino acid compositions. The half-IgG was found to contain abnormally high quantities of carbohydrate, -17% by weight. The monomeric and aggregated immunoglobulins had much lower levels of carbohydrate (
