陰道毛滴蟲(Trichomonas vaginalis)是導致性疾病中的一種單細胞，其中的基因蛋白，親環蛋白(cyclophilin)，此是陰道毛滴蟲的感染主要因子，一個蛋白的結構涉入蛋白的功能以及活性，為了瞭解病理機致我們要分析Trichomonas vaginalis cyclophilin的結構，結構又與雙硫鍵(disulfide bonds)有極大關係。
利用實驗室建立的254nm紫外光(Ultraviolate UV)流動槽系統結合液相層析Liquid Chromatography (LC)來照射醇類與丙酮溶劑，產生對雙硫鍵有還原作用的自由基，由此再運用質譜儀 Mass Spectrometry (MS)來解析蛋白質的雙硫鍵。
用 UV 系統來分析陰道毛滴蟲細胞裡選殖出來的重組基因蛋白Recombinant Trichomonas vaginalis cyclophilin (r-TvCyP)，r-TvCyP1與 r-TvCyP2的雙硫鍵(disulfide linkages)已經被分析出來，兩者具有相同序列的雙硫鍵之鍵結(disulfide linkages)，C153-C164及 C41-C169。
對 r-TvCyP3進行雙硫鍵分析，在 intact 蛋白部分，發現 r-TvCyP3具有高度的氧化及306 Da的加合物(adduct)，利用 UV 系統及蛋白變性態的實驗推斷出 adduct 就是Glutathione。從照光系統知道 Refold 的r-TvCyP3的9個半胱胺酸 (Cysteine, C)中，C39及 C41照光後還原的比例(UV reduced free Cysteine%)為100%，表示這兩個 Cysteine存在於 disulfide linkages 中，且 C39與 C41是相連在一起；C59在照光後還原的比例高達96%，表示 C59大部分存在於 disulfide linkages中；C81是 Glutathione 的主要位點，照光後有55%(free Cysteine%)的加合物，而其在照光後還原的比例有25%，表示 C81有部分存在於 disulfide linkages中；C127在照光前後都有高比例的氧化(free Cysteine%)，且其是 r-TvCyP3一個氧修飾的主要位點，表示其本身的硫醇(thiol)是 free thiol，C135則是 Glutathione 的第二位點，也具有氧化的比例(free Cysteine%)，其 thiol 也是 free thiol，兩者都可以從 r-TvCyp1與 r-TvCyp2的 free thiol 證實；C153、C164與 C169在照光後還原的比例為100%，表示這3個 Cysteine是存在於 disulfide linkages 中；利用照光前的層析圖找到 disulfide linkages的組合(disulfide bonds mapping)，Refold 與 Reconstitution 的 r-TvCyp3皆是以 C153-C164/ C81-C169與 C164-C169這三種disulfide linkages，其中 C153-C164與 C164-C169也存在於 r-TvCyP1。

Trichomonas vaginalis cyclophilin is related to the sexual disease, if we know its structure maybe can realize the pathological mechanism.
To analyze the recombinant Trichomonas vaginalis cyclophilin (r-TvCyP) is our purpose, r-TvCyP1 and r-TvCyP2 have been published by this way, the rest of r-TvCyP protein is r-TvCyP3 we need to analyze and accomplish r-TvCyP series.
Using Ultraviolate (UV) reduction system we established by a Liquid Chromatography (LC) connected with flow cell by fuse silica tube in front of MASS (MS) to detect the reduction of the disulfide bonds. When acetone is under 254 nm UV exposed, it will generate acetyl radicals to attack alcohol, and then secondary hydroxyalkyl radicals resulting from alcohol solvent are responsible for cleaving the disulfide bonds.
For analysis of r-TvCyP3, in intact Protein, we find that there are oxidation and 306 adduct on r-TvCyP3, we deduce 306 adduct is Glutathione (GSH) by UV reduction and denatured digestion. In data analysis, we know totally 9 Cysteine (C) in r-TvCyP3, C39 and C41 has 100% UV reduced free Cysteine% after UV reduction, both are connected with intra disulfide bonds ; C59 has arrived 96.5% of UV reduced free Cysteine% after UV reduction, it means C59 exists in disulfide linkages before UV reduction; C81 is the main site of Glutathione, has around 55% (free Cysteine%) adduct, but it also has 25% of UV reduced free Cysteine% after UV reduction, means it also has a quarter existing in disulfide linkages ; Peptide contained C127 and C135 have high oxidative percentage(free Cysteine%) from their free thiol which can be verified by r-TvCyP1 and r-TvCyP2. Furthermore, C135 also is the second site of Glutathione ; C153, C164 and C169 have 100% UV reduced free Cysteine% after UV reduction, it means C153, C164 and C169 exist in disulfide linkages before UV reduction. The disulfide linkages of Refold and Reconstitution r-TvCyp3 are C153-C164/ C81-C169 and C164-C169, in addition, C153-C164 and C164-C169 also exsit in r-TvCyP1.

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