台灣東岸與西岸眼鏡蛇(Naja atra)除了外觀上與毒性上有差異，在心臟毒素同源蛋白的比例上也發現相當顯著的差別，由於目前對於高分子量的蛋白所知有限，因此本實驗針對東、西岸台灣眼鏡蛇蛇毒中含量較少的高分子量蛋白作比較與鑑定。實驗中主要利用快速蛋白液相層析儀及十二烷基磺酸鈉-聚丙烯醯胺膠電泳將高分子量的蛋白分離，再用基質輔助雷射脫附游離/飛行時間質譜儀比對大於20kD的高分子量蛋白，並比對出眼鏡蛇蛇毒因子、Kaouthiagin-like和Cobrin-like。定量分析結果發現東岸台灣眼鏡蛇的眼鏡蛇毒因子含量大於西岸台灣眼鏡蛇(約4.5%和1.5%)，而Kaouthiagin-like和Cobrin-like在東、西岸台灣眼鏡蛇蛇毒的含量並無明顯差別。另外實驗中也發現三種高分子成分(眼鏡蛇蛇毒因子、Kaouthiagin-like和Cobrin-like)都具有N-鍵結的醣化修飾作用，其中Cobrin-like是一種蛇毒金屬蛋白水解酵素，結果顯示去醣化會使得Cobrin-like產生聚集的現象，導致失去酵素活性，無法分解纖維蛋白的α-鏈，因此醣化的修飾對於眼鏡蛇蛇毒中的蛇毒金屬蛋白水解酵素，必定扮演十分重要的角色。

In addition to the differences of morphology and toxicity between Eastern and Western Taiwan Cobra (Naja atra), it has recently been shown that the concentration of CTXs from Eastern and Western are also significantly different. However, it is not known whether high molecular weight proteins in snake venom. In this study, we compare and identify high molecular weight protein (over 20kD) components of venoms between Eastern and Western Taiwan Cobra. Three high molecular weight components (CVF, Cobrin-like and Kaouthiagin-like)in snake venom were separated by FPLC followed by SDS-PAGE and identified by MALDI-TOF MS. Quantitative analysis showed that the Eastern Taiwan Cobra contains higher amount of CVF than the Western Taiwan Cobra (~4.5% and ~1.5%). However, there are no significant differences in Cobrin-like and Kaouthiagin-like. Three high molecular weight components (CVF, Cobrin-like and Kaouthiagin- like) are also found to be glycoprotein with N-linked glycosylation. Deglycosylation of Cobrin-like, a group of SVMP which hydrolyzes α-chain of fibrinogen, induce a protein aggregation and lose its enzyme activity. It was suggested that glycosylation might play an important role in regulating snake venom metalloproteinase activities of snake venom components.

1. CTX：Cardiotoxin

2. FPLC：Fast Protein Liquid Chromatography

3. SDS-PAGE：Sodium Dodecyl Sulfate-Polyacrylamide Gel Electrophoresis

4. MALDI-TOF MS：Matrix-Assisted Laser Desorption Ionization-Time of
Flight Mass Spectrometry

5. CVF：Cobra Venom Factor

6. SVMP：Snake venom metalloproteinase

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