LENS TRANSGLUTAMINASE AND CATARACT FORMATION
LENS TRANSGLUTAMINASE AND CATARACT FORMATION
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DOI：
10.1073/pnas.78.3.1356
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发表时间：
1981-01-01
期刊：
影响因子：
--
通讯作者：
RAFFERTY, NS
中科院分区：
文献类型：
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作者：
LORAND, L;HSU, LKH;RAFFERTY, NS
人白内障中特征性存在的蛋白质聚合物含有显著量的γ-谷氨酰-ε-赖氨酸异肽。这些交联可以通过转氨酶（R-氨基-肽：胺-γ-氨基-β-氨基-β-β-氨基-β-氨基-β-β-谷氨酰转移酶，EC 2.3.2.13）;透镜含有该酶及其内源性蛋白质底物。在透镜皮质中发现最高的表观活性。当在Ca 2+存在下将来自兔的皮质匀浆与[14 C]腐胺或丹磺尸胺一起孵育时，放射性或荧光胺选择性掺入较重亚基（MW约为100）中。26，000和30，000）的β-可以证明晶体蛋白。调节这种酶在透镜的交联活性的可能模式进行了讨论。
A protein polymer characteristically present in human cataract contained significant amounts of .gamma.-glutamyl-.epsilon.-lysine isopeptides. These crosslinks may be produced by the action of transglutaminase (R-glutaminyl-peptide:amine-.gamma.-glutamyl-yltransferase, EC 2.3.2.13); lens contains the enzyme and endogenous protein substrates for it. The enzyme is similar to that obtained from liver and is Ca2+ dependent. Highest apparent activity is found in lens cortex. When cortex homogenate from the rabbit was incubated in the presence of Ca2+ with either [14C]putrescine or with dansylcadaverine, a selective incorporation of the radioactive or fluorescent amine into the heavier subunits (MW .apprxeq. 26,000 and 30,000) of .beta.-crystallins could be demonstrated. Possible modes of regulating the crosslinking activity of this enzyme in lens are discussed.