Fu Ling, Liang Jack J N
Center for Ophthalmic Research, Brigham and Women's Hospital, and Department of Ophthalmology, Harvard Medical School, 221 Longwood Ave, Boston, MA 02115, USA.
FEBS Lett. 2002 Feb 27;513(2-3):213-6. doi: 10.1016/s0014-5793(02)02313-x.
Human lens gammaC-crystallin and T5P mutant were cloned, and their biophysical properties and thermodynamic stability were studied. CRYGC (T5P) is one of the many gamma-crystallin mutant genes for autosomal dominant congenital cataracts. This mutation is associated with Coppock-like cataract, and has the phenotype of a dust-like opacity of the fetal lens nucleus. During cloning and overexpression, the majority of T5P mutant was found in the inclusion body. This property is unique among the many cataract gamma-crystallin mutant genes. It is thus worthwhile to study what factors contribute to this unique property of gammaC-crystallin. One possibility is changes in conformation and stability, which can be studied using spectroscopic measurements. In this study, conformational change was studied by circular dichroism and fluorescence measurements, and conformational stability was determined by thermal unfolding probed by Trp fluorescence and time-dependent light scattering. The T5P mutation obviously changes conformation and decreases conformational stability.
克隆了人晶状体γC-晶状体蛋白及其T5P突变体，并对其生物物理性质和热力学稳定性进行了研究。CRYGC（T5P）是常染色体显性先天性白内障众多γ-晶状体蛋白突变基因之一。这种突变与类科波克样白内障有关，具有胎儿晶状体核呈粉尘样混浊的表型。在克隆和过表达过程中，发现大多数T5P突变体存在于包涵体中。在众多白内障γ-晶状体蛋白突变基因中，这一特性是独特的。因此，研究哪些因素导致γC-晶状体蛋白的这种独特特性是值得的。一种可能性是构象和稳定性的变化，可以通过光谱测量来研究。在本研究中，通过圆二色性和荧光测量研究构象变化，通过色氨酸荧光和时间依赖性光散射探测的热变性来确定构象稳定性。T5P突变明显改变构象并降低构象稳定性。
