Malloch G D, Clark J B, Burnet F R
J Neurochem. 1987 Jan;48(1):299-306. doi: 10.1111/j.1471-4159.1987.tb13162.x.
The distribution of glial fibrillary acidic protein (GFAP) into cytoskeletal and soluble protein fractions during development of the rat brain has been studied by quantitative immunoblotting and enzyme-linked immunosorbent assay (ELISA). These assays indicate that cytoskeletal GFAP accounts for nearly all the total GFAP in the adult rat brain, and that the developmental increase in the GFAP content of the rat brain is due to accumulation of GFAP into the cytoskeleton. A small and constant amount of the total GFAP was detected in the soluble protein fraction. This GFAP had an apparent molecular mass (Mr) similar to that of the highest Mr form of GFAP detected in the cytoskeletal fraction. In contrast to the assays for cytoskeletal GFAP, no significant increase in the GFAP concentration of the soluble protein fraction could be measured during development. Sensitive, calibrated immunoblotting of cytoskeletal and soluble protein with [125I]protein A confirmed these findings, and showed that both cytoskeletal and soluble GFAP are first detected during the same period of foetal rat brain development. A finite and reproducible amount of lower Mr forms of GFAP were observed in the cytoskeletal fraction even when prepared in the presence of stringent proteolytic inhibitors. These presumed proteolytic degradation products of GFAP increased in abundance during development, parallel to the increase in cytoskeletal GFAP content of the rat brain. However, the abundant proteolytic degradation products of GFAP found in the cytoskeletal fraction were not detected in the soluble protein fraction at any age studied.(ABSTRACT TRUNCATED AT 250 WORDS)
通过定量免疫印迹法和酶联免疫吸附测定（ELISA），研究了大鼠脑发育过程中胶质纤维酸性蛋白（GFAP）在细胞骨架和可溶性蛋白组分中的分布情况。这些测定表明，细胞骨架GFAP几乎占成年大鼠脑中总GFAP的全部，并且大鼠脑GFAP含量的发育性增加是由于GFAP在细胞骨架中的积累。在可溶性蛋白组分中检测到少量且恒定的总GFAP。这种GFAP的表观分子量（Mr）与在细胞骨架组分中检测到的最高Mr形式的GFAP相似。与细胞骨架GFAP的测定相反，在发育过程中未检测到可溶性蛋白组分中GFAP浓度有显著增加。用[125I]蛋白A对细胞骨架和可溶性蛋白进行灵敏的校准免疫印迹证实了这些发现，并表明细胞骨架和可溶性GFAP都是在大鼠胎儿脑发育的同一时期首次被检测到。即使在存在严格的蛋白水解抑制剂的情况下制备，在细胞骨架组分中也观察到有限且可重复量的较低Mr形式的GFAP。这些推测的GFAP蛋白水解降解产物在发育过程中丰度增加，与大鼠脑细胞骨架GFAP含量的增加平行。然而，在所研究的任何年龄的可溶性蛋白组分中均未检测到在细胞骨架组分中发现的大量GFAP蛋白水解降解产物。（摘要截短至250字）
