RACEMIZATION IN HUMAN LENS - EVIDENCE OF RAPID INSOLUBILIZATION OF SPECIFIC POLYPEPTIDES IN CATARACT FORMATION
RACEMIZATION IN HUMAN LENS - EVIDENCE OF RAPID INSOLUBILIZATION OF SPECIFIC POLYPEPTIDES IN CATARACT FORMATION
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DOI：
10.1073/pnas.75.8.3618
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发表时间：
1978-01-01
影响因子：
11.1
通讯作者：
SPECTOR, A
中科院分区：
文献类型：
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作者：
GARNER, WH;SPECTOR, A
在生命早期，正常人晶状体的干重随着时间的推移以相对恒定的速度增加。从可溶物质到不可溶物质的转变似乎以类似的速度发生，导致可溶物质的数量保持不变。在白内障中，不溶化速度加快。D-天冬氨酸/L-天冬氨酸比值的测定支持了上述观察结果。在正常晶状体中，D-天冬氨酸的丰度随着年龄的增长而以恒定的速度增加，而在可溶部分中D-天冬氨酸的丰度没有变化。在白内障晶状体中，不溶性成分的比例显着降低。对从还原和烷基化的可溶和不溶的白内障晶状体蛋白中分离出的多肽的检查和其他数据表明了以下额外的结论：不溶部分中的10,000道尔顿多肽部分来自一种已经不溶的前体的降解；而D-天冬氨酸在白内障晶状体不溶部分中的丰度降低主要是由于43,000和20,000道尔顿范围组分的快速不可溶。
After early life, the dry weight of normal human lenses increases at a relatively constant rate with time. Transformation from soluble to insoluble material appeared to occur at a comparable rate, resulting in a constant amount of soluble material. In cataract the insolubilization rate was accelerated. These observations were supported by determination of D-aspartic acid/L-aspartic acid ratios. The abundance of D-aspartic acid increased with aging at a constant rate in the insoluble fraction of normal lenses but did not change in the soluble fraction. In cataractous lenses there was a significant decrease in the ratio in the insoluble fraction. Examination of polypeptides isolated from reduced and alkylated soluble and insoluble cataractous lens protein and other data suggested the following additional conclusions: the 10,000 dalton polypeptide in the insoluble fraction was derived in part from degradation of an already insoluble precursor; and the lowered abundance of D-aspartic acid in the insoluble fraction of cataractous lenses was primarily due to the rapid insolubilization of the 43,000 and 20,000 dalton range components.