臺灣博碩士論文加值系統

本論文是以水生無脊椎動物斑節蝦的眼為材料, 藉以鉎鈦受質 KLKCFFL
的酵素活性檢測,先後經過 HiTrp Q 陰離子交換管柱層析, Superdex 200
膠體過濾管柱層析, Mono Q 陰離子交換管柱層析, 最後以鉎鈦偶合親和
力管柱完成蛋白質角牛兒角牛兒基轉移脢I (PGGT I) 的純化. 純化的
PGGT I 比活性為 188 units/mg. 從膠體過濾管柱層析估算的分子量為67
kDa 與 SDS-PAGE 所估算的 67 kDa 相近, 推測斑節蝦 PGGT I 為單體.
所得的蛋白質能被抗法呢基轉移脢 alpha 次單元的抗體 (Y-53) 所辨認,
顯示二者含有相似的胺基酸序列. 在所檢測的鉎鈦中, KCFFL 是較好的
鉎鈦受質. 酵素作用最適的酸鹼值是 pH 8.0. 斑節蝦 PGGT I 證實是金
屬性脢 (EDTA 的 I.C.50=0.00025 mM) 但活性會受 Mg++ (I.C.50=0.5
mM) 及 Zn++ (I.C.50=0.05 mM) 所抑制. PGGT I 廣布於斑節蝦的眼,肝
胰臟,心臟,鰓,神經節,腸,肌肉及殼各組織.

Protein geranylgeranyltransferase I was purified from the eyes
of shrimp Penaeus japonicus by the sequential column
chromatography on HiTrap Q, Superdex 200, Mono Q and peptide-
coupled affinity column. The purified enzyme was found to have
relative Mr of 66 kDa as estimated by SDS-PAGE. Since the active
protein geranylgeranyltransferase I from Superdex 200 was found
to have relative mass of 67 kDa, the purified enzyme was deduced
to be a monomer. Synthetic peptide KCFFL is the best substrate
fo the protein geranylgeranyltransferase I among the
investigated peptides. The optimal pH for enzyme activity is pH
8.0. The enzyme was inhibited by Mg++ and Zn++ ions at 0.05 mM
and 0.5 mM respectively. Since EDTA (I.C.50=0.00025 mM) is
inhibitory as well, the protein geranylgeranyltransferase I of
penaeus japonicus is a metaloenzyme.