甘藷塊根蛋白質磷酸脢之純化與性質分析

The Purification and Characterization of Protein Phosphatase from Sweet Potato Roots

林俊良(Chun-Liang Lin)

指導教授 ： 莊榮輝

國立臺灣大學/生命科學院/微生物與生化學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00592

摘要

可逆性的蛋白質磷酸化，是細胞常見的訊息傳導機制之一；藉由蛋白質激脢與磷酸脢相互拮抗的磷酸化活性來調控。本論文以甘藷塊根為材料，利用硫酸銨分劃、親合層析、離子交換層析、膠體過濾層析等純化步驟，得到四類不同的磷酸脢，且分別命名為 P I, P II, P III, P IV。其中 P II經由定序結果得知為一甘藷體內的酸性磷酸脢。藉由不同基質的磷酸脢活性分析結果，與以放射線磷酸標定之磷酸化 L-SP為基質的活性分析結果比對，發現純化所得之四類磷酸脢雖然對其他基質具有高度活性，但無法對磷酸化 L-SP進行去磷酸化反應。添加金屬離子作為 cofactor或加入抑制劑也無法觀察到對磷酸化 L-SP進行去磷酸化的活性改變。推測甘藷塊根在此一生長時期，無對磷酸化 L-SP具專一性之磷酸脢存在。

關鍵字

磷酸脢 ； 澱粉磷解脢

並列摘要

The reversible phosphorylation/dephosphorylation of protein is one of the common but important cell regulation mechanisms in the cell. The L-form starch phosphorylase from sweet potato root could be phosphorylated by LSK in vitro. In this study, we partially purified four phosphatases by ammonium sulfate fractionation, ion exchange, gelfiltration, and affinity chromatography, and termed PI, PII, PIII, and PIV. PII was shown to be a purple acid phosphatase. Differences in pH optima, phosphatase inhibitors, and response to divalent cations indicate that these phosphatases showed no dephosphorylation activity on the phosphorylated L-SP, which was phosphorylated by LSK. Those results were indicated that the sweet potato roots in this stage might be no related phosphatase to dephosphorylate L-SP.

並列關鍵字

phosphatase ； starch phosphorylase

參考文獻

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