Synthesis of β2-Microglobulin by Stimulated Lymphocytes

[摘要] β2-microglobulin is a human serum protein of low molecular weight and unknown function (1). Normally present in serum in low concentrations (2 µg/ml), it is degraded by the kidney (2). In the presence of renal failure serum concentrations as high as 70 µg/ml may occur (3, 4). Patients with defective renal tubular function excrete increased amounts of β2-microglobulin in their urine (4), suggesting that tubular reabsorption is an important step in the catabolism of this protein. In its dependence upon the kidney for degradation, β2-microglobulin is similar to immunoglobulin light chains (5), although microglobulin is not antigenically related to any known immunoglobulin.Recently, Smithies and Poulik have reported the partial amino acid sequence of β2-microglobulin (6). They found significant homology between β2-microglobulin and two adjacent loops (C2 and C3) of the heavy chain of human γG globulin. This finding suggested that β2-microglobulin might be synthesized in lymphoid tissue and prompted us to investigate whether this protein was produced by lymphocytes during in vitro culture.

[学科分类] 生物科学（综合）