| Abstract: |
Prostaglandin endoperoxide synthase has been purified from the recently established human lung tumor cell line, Lu-65. By gel filtration, the purified enzyme migrated with a relative molecular weight of 115000, unlike the ovine enzyme, which migrated at 155000. Two protein bands of 45000 and 68000 were seen when the purified Lu-65 enzyme was fractionated under reducing conditions by SDS-polyacrylamide gel electrophoresis; in contrast, purified ovine prostaglandin endoperoxide synthase showed the Mr 68000 band under the same conditions. The purified Lu-65 enzyme showed both cyclooxygenase and hydroperoxidse activities, and metabolized [3H]arachidonic acid to 3H-labeled products that, when separated by reverse-phase HPLC, co-eluted with authentic prostaglandin D2 and prostaglandin E2. An apparent Km for arachidonic acid of 3 mM was measured for the purified enzyme, and the crude membrane-bound enzyme showed an apparent Km of 1.6 mM. Under the same conditions, an apparent Km of 17 μ M was measured for the purified ovine enzyme. © 1986. |
| Keywords: |
human cell; animal; lung neoplasms; cell line; in vitro study; lung tumor; kinetics; chromatography, high pressure liquid; arachidonic acid; prostaglandins e; molecular weight; chromatography, gel; electrophoresis, polyacrylamide gel; cyclooxygenase; dinoprostone; respiratory system; sheep; prostaglandin synthase; human; priority journal; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; prostaglandin-endoperoxide synthase; arachidonic acids; prostaglandin endoperoxide synthase; prostaglandin d2; (human lung cell); prostaglandins d
|
