本計畫執行中由二十九個不同年齡個體取得檢體,成功建立並維持九株纖維母細胞株。細胞株由低代培養至高代其形態變化和前人報告相似。我們在第五至十代間測定了這些細胞株中一可修復老化受損蛋白質的L-isoaspartyl蛋白質甲基轉移？(PCM)的活性。其強弱和細胞株採樣個體年齡相關性不明顯。另並對FA-2(來自一九歲男性)和FA-10 (來自一五十七歲女性)兩細胞株,每隔一代測甲基轉移？活性至第三十代。隨培養代數增至高代,酵素活性亦呈增加趨勢。纖維母細胞中甲基接受者之量以重組之人類甲基轉移？為酵素來源測定之,其亦有隨代數增加之趨勢。本研究結果為老化中含L-isoaspartyl氨基酸殘基蛋白質之代謝貢獻良多。 Twenty nine human biopsy samples were collected and nine fibroblast strains have been established and maintained. The morphological changes of these fibroblast strains cultivated from low to high population level were as reported. We determined the activity of the enzyme D-aspartyl/L-isoaspartyl protein carboxyl methyltransferase that has been proposed to repair age-damaged proteins in these fibroblast cells between passage 5 to 10. No significant relation of the methyltransferase activity and the age of the fibroblast donor have been observed. In two fibroblast strains FA-2 (from a nine year old male) and FA-10 (from a 57 year old female) the activities have been determined every other passages up to the thirtieth passage. Elevated activity have been observed in both strains with increased passages. The level of methyl accepting substrates also increases with passages. The results of this project contribute to the understanding of the relationship of the L-isoaspartyl methyltransferase with aging.
