Proteins in multiple myeloma. VIII. Biosynthesis of abnormal proteins

F W PUTNAM, A MIYAKE
1958 Journal of Biological Chemistry  
Multiple myeloma is an invariably fatal tumor of the plasma cells, which are thought to be involved in antibody production. The disease is generally accompanied by hyperglobulinemia, Bence-Jones proteinuria, or both aberrations in protein synthesis. Although both the myeloma serum globulin and the unique urinary protein are thought to be formed within the tumor cell, no metabolic relationship has yet been demonstrated between the two types of abnormal proteins. Furthermore, accumulating
more » ... indicates not only that different patients produce individually characteristic globulins that are related to normal serum proteins (1, 2), yet distinguishable from them, but also that the Bence-Jones proteins excreted by different patients are not identical (3, 4). Previous study with N16-glytine and with glycine-l-Cl3 has refuted the hypothesis that the Bence-Jones proteins are derived by renal cleavage of the abnormal serum globulins and has suggested that the two types of pathological proteins may be synthesized independently (5, 6). These experimental results, since confirmed (7-9), did establish that the urinary protein is rapidly formed from the administered amino acids and is rapidly excreted. In order to investigate further whether the synthesis of Bence-Jones protein is related to that of the myeloma globulin, 450 ~.rc. of nn-glutamic acid-l-C'* were injected into a patient who was catheterized to permit frequent withdrawal of blood and urine specimens. The accompanying paper (10) has described the subject and protocol of the experiment and the metabolic fate of the racemic amino acid; this communication reports the data relevant to the biosynthesis of the abnormal proteins. Significant radioactivity was not detected in either the Bence-Jones protein or the myeloma globulin until about 40 minutes after injection. The subsequent time-course of radioactivity is discussed in terms of possible biosynthetic relationships between the two abnormal proteins.
pmid:13539002 fatcat:jdot6kzdwvdpvlsq3yjjuqu4ze