本研究中，我們研發了新的固相化學交聯方法學。在agarose beads 之上接上化學交聯試劑SAED，此反應劑可以選擇性地收集到生物分子聚體表面的蛋白質並進一步鑑定其身份。比較某一特定蛋白質在beads收集到的樣品與在原本總蛋白質中量的差異，可以得知該蛋白質在此生物分子聚體中空間分佈的資訊。本研究中我們先以一個已知結構的系統，synthetic three-layered protein complex，來驗證此新方法學的正確性。再利用此經驗證過的方法學，來分析豬大腦後突觸質密區組成蛋白質之間的排列結構。
我們決定了後突觸質密區之中5個主要蛋白質和19個次要蛋白質位於後突觸質密區的表面或內層。結果顯示，dynein intermediate chain、AMPA receptors、kainate receptors、N-cadherin、β-catenin、N-ethylmaleimide-sensitive factor、heat shock 70 kDa protein 8 isoform 2以及actin等蛋白質主要位居於表面。α,β-tubulin subunits、dynein heavy chain、MAP2A/2B、MAP2C/2D、spectrin、neurofilament heavy subunits、neurofilament medium subunits、heat shock 70 kDa protein 12A、α-internexin、dynamin-1 以及PSD-95位居於深度3.5 nm以內的區域。N-methyl-D-aspartate receptors 以及α-subunits of calcium, calmodulin-dependent protein kinase II位於表面但卻形成或位處於特殊的結構中。基於我們的實驗結果，並結合前人對於後突觸質密區組成蛋白質之間接合關係的了解，我們提出了PSD構造的分子模型。

Agarose beads carrying a cleavable, fluorescent, and photoreactive cross-linking reagent on the surface were synthesized and used to selectively pull out the proteins lining the surface of supramolecules. A quantitative comparison of the abundances of various proteins in the sample pulled out by the beads from supramolecules to their original abundances could provide the information on the spatial arrangement of these proteins in the supramolecule. The usefulness of these synthetic beads was successfully verified by trials using a synthetic protein complex consisting of three layers of different proteins on glass coverslip.
By using these beads, we determined the interior or superficial locations of 5 major and 19 minor constituent proteins in the postsynaptic density (PSD), a large protein complex and the landmark structure of asymmetric synapses in the mammalian CNS. The results indicate that α,β-tubulins, dynein heavy chain, microtubule-associated protein 2, spectrin, neurofilament H and M subunits, a hsp70 protein, α-internexin, dynamin and PSD-95 protein reside in the interior of the PSD. Dynein intermediate chain, AMPA receptors, kainate receptors, N-cadherin, β-catenin, N-ethylmaleimide-sensitive factor, a hsc70 protein and actin reside on the surface of the PSD. The results further suggest that the N-methyl-D-aspartate receptors and the α-subunits of calcium, calmodulin-dependent protein kinase II are likely to reside on the surface of the PSD with, however, unique local protein organizations. Based on our results and the known interactions between various PSD proteins from data mining, a model for the molecular organization of the PSD is proposed.

李慧貞(2002), 後突觸質密區中新鑑定的蛋白質-PSD500之研究 / Identification and characterization of a novel protein-PSD500 in the postsynaptic densities, 國立清華大學生命科學系碩士論文
古美雲(2003), 利用二維電泳法分析鼠腦之後突觸質密區(PSD)與其主要蛋白α-CaMKII / Analysis of postsynaptic density and α-CaMKII in rat brain by two-dimensional gel electrophoresis, 國立清華大學分子醫學研究所碩士論文
游珮均(2006), 利用化學交聯法分析後突觸質密區(PSD)之蛋白結構 / Analysis of protein organization of the postsynaptic density by chemical cross-linking method, 國立清華大學分子醫學研究所碩士論文
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