豬髓磷質鹼性蛋白質之化學修飾研究

Abstract

以豬髓磷質鹼性蛋白質(porcine myelin basic protein)為材料，利用化學修飾法(chemical modification)選擇修飾其中的色胺酸(Trp)，修飾程度分別為0.74個色胺酸(以NPS-C1修飾)及1個色胺酸(以DISA修飾)，造成鹼性蛋白質致腦脊髓炎能力(EAE activity)的下降，但修飾後的鹼性蛋白質，以CD分析結果來看，其分子結構並無改變，顯見單一一個色胺酸對鹼性蛋白質導致腦脊髓炎發生的重要性。

Reactio?s of porcine myelin basic protein with both nitrophenylsulfenyl chloride (NPS-C1) and 2,3-dioxo-5-indolinesulfonic acid (DISA) yielded homogeneous derivatives which were modified at a single tryptophan residue. The absorption spectrums of both derivatives showed new peaks in the visible range with max at 365nm. CD measurements gave similar values for porcine myelin basic protein and its derivatives. Although no conformational differences were observed by CD measurement, the EAE activities of both derivatives were greatly decreased. It suggested that a single Trp residue was essential for the myelin basic protein for induction of EAE activity.