Abstract
The effect of the 2′,5′-adenylate and cordycepin trimer cores on DNA and protein synthesis in human umbilical cord lymphocytes, lymphoblasts, peripheral blood lymphocytes and Epstein-Barr virus infected lymphocytes and their metabolism in tissue culture medium have been studied. [32P]Adenylate and [32P]- and [3H]cordycepin trimer cores were synthesized either enzymatically or chemically and added to cells in culture. The half-lives of the 2′,5′-A3 core and 2′,5′-3′dA3 core in tissue culture were 3 and 17 hr, respectively. Chromatographic analysis of the TCA-soluble extracts of the lymphocytes and lymphoblasts treated with 2′,5′-[3H]A3 showed that 0.25% of the 32P was identified as AMP, ADP, ATP and inorganic phosphate. By the more sensitive 2′,5′-p3A4[32P]pCp radiobinding assay, 2′,5′-A3 was detected in the TCA supernatants; however, there was no 5′-rephosphorylation. With the [3H]- and [32P]cordycepin trimer core, 0.55% and 1.3% of the radioactivity was in the TCA soluble extracts. Although there was no 5′-rephosphorylation as determined by radiobinding assay, the intact cordycepin trimer core was detected by tlc, radiobinding assay, and HPLC.
Furthermore, in two experiments, the concentration of the cordycepin trimer core bound to or taken up by the lymphocytes was three-fold greater than the concentration in the medium. 2′,5′-A3 and 2′,5′-3′dA3 cores were both antimitogenic, but did not inhibit protein synthesis.