Evidence for the in-vitro de-novo synthesis of immunoglobulin and a previously undescribed 17 kDa protein (TEP-2) by the mucosa of the fallopian tube.

De-novo synthesis and secretion of proteins by short-term explants of matched Fallopian tube mucosa and endometrium were studied using radiolabelled L-[35S]methionine and [3H]glucosamine. To compare directly each anatomical site of the Fallopian tube and endometrium from the same source, newly synthesized proteins were separated on one-dimensional polyacrylamide gel electrophoresis and examined by auto-radiography. De-novo synthesis of two protein bands provisionally designated as tubal epithelial protein 1 (TEP-1) and tubal epithelial protein 2 (TEP-2), was observed in explants of the Fallopian tube mucosa obtained from each anatomical site throughout the ovarian cycle (n = 20). TEP-2 was not apparent in tubal mucosa obtained from post-menopausal women (n = 5). De-novo synthesis of TEP-1 and TEP-2 was not apparent in autoradiographs of radiolabelled proteins from short-term explants of endometrium. From the autoradiographs the molecular mass of TEP-1 and TEP-2 was calculated to be 25 kDa and 17 kDa, respectively. Incorporation of glucosamine into newly synthesized protein occurred in TEP-2 but not TEP-1. TEP-1 was observed to be immunochemically identical to immunoglobulin kappa light chains.