Brain transglutaminase: in vitro crosslinking of human neurofilament proteins into insoluble polymers.
Brain transglutaminase: in vitro crosslinking of human neurofilament proteins into insoluble polymers.
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脑转谷氨酰胺酶：在体外将人神经丝蛋白交联成不溶性聚合物。
DOI：
10.1073/pnas.79.19.6070
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发表时间：
1982
影响因子：
11.1
通讯作者：
Ihara,Y
中科院分区：
文献类型：
--
作者：
Selkoe,DJ;Abraham,C;Ihara,Y
在衰老的人类神经元中积累的不溶性、高分子量丝状聚合物显然是由非二硫共价键连接的，这使我们研究了人脑中转谷氨酰胺酶（EC 2.3.2.13）和这种交联酶的内源性蛋白质底物的存在。我们证明了在大脑中存在一种转氨酶，它可以通过形成γ -谷氨酰- ε -赖氨酸分子间桥，将脑蛋白共价交联成体外不溶性聚合物。脑转谷氨酰胺酶依赖于Ca2+，具有类似于红细胞转谷氨酰胺酶的电泳迁移率，并且在老年正常人和阿尔茨海默病（老年性痴呆）患者的死后大脑中活跃。在谷氨酰胺转胺酶、Ca2+和荧光胺丹糖尸胺的存在下培养的脑神经丝部分形成一种荧光的、非二硫键的不溶性聚合物；这一过程与制剂中可溶性神经丝多肽量的减少有关。聚合物材料的电子显微镜显示了一个广泛的连接细丝的网络，可以用各种神经丝抗血清免疫染色。半胺，一种谷氨酰胺转胺酶抑制剂，阻止神经丝交联。神经胶质丝和髓鞘碱性蛋白也可作为脑转谷氨酰胺酶的底物。尽管在特定的体外条件下，阿尔茨海默病类型的成对螺旋细丝没有形成，但这些数据表明，在人类神经元衰老过程中，细丝共价交联成不溶性聚合物的一种可能机制。
The accumulation in aged human neurons of insoluble, high molecular weight filamentous polymers apparently linked by nondisulfide covalent bonds led us to examine human brain for the presence of transglutaminase (EC 2.3.2.13) and endogenous protein substrates for this crosslinking enzyme. We demonstrate the presence in brain of a transamidating enzyme that can covalently crosslink brain proteins into insoluble polymers in vitro by forming gamma-glutamyl-epsilon-lysine intermolecular bridges. Brain transglutaminase is Ca2+ dependent, has an electrophoretic mobility similar to that of erythrocyte transglutaminase, and is active in human postmortem brain from aged normal individuals and patients with Alzheimer disease (senile dementia). Brain neurofilament fractions incubated in the presence of transglutaminase, Ca2+, and the fluorescent amine dansylcadaverine form a fluorescent, nondisulfide-bonded insoluble polymer; this process is associated with a decrease in the amount of soluble neurofilament polypeptides in the preparation. Electron microscopy of the polymeric material reveals an extensive network of connecting filaments, which can be immunostained with various neurofilament antisera. Cystamine, an inhibitor of transglutaminase, prevents the neurofilament crosslinking. Glial filaments and myelin basic protein can also serve as substrates of brain transglutaminase in vitro. Although Alzheimer disease-type paired helical filaments are not formed under the specific in vitro conditions employed, the data suggest one possible mechanism for the covalent crosslinking of filaments into insoluble polymers during human neuronal aging.
DOI：
10.1177/000348947508400320
发表时间：
1975
期刊：
Annals of Otology, Rhinology & Laryngology
影响因子：
--
作者：
P. Bucy
通讯作者：
P. Bucy