Small-angle X-ray scattering studies of the intact eye lens: Effect of crystallin composition and concentration on microstructure

被引:17
作者
Mirarefi, Amir Y. [2 ]
Boutet, Sebastien [3 ]
Ramakrishnan, Subramanian [1 ]
Kiss, Andor J. [4 ]
Cheng, Chi-Hing C. [5 ]
DeVries, Arthur L. [5 ]
Robinson, Ian K. [3 ]
Zukoski, Charles F. [2 ]
机构
[1] FAMU FSU Coll Engn, Dept Chem & Biomed Engn, Tallahassee, FL 32310 USA
[2] Univ Illinois, Dept Chem & Biomol Engn, Ctr Biophys & Computat Biol, Urbana, IL 61801 USA
[3] Univ Illinois, Dept Phys, Urbana, IL 61801 USA
[4] Miami Univ, Dept Zool, Lab Ecophysiol Cryobiol, Oxford, OH 45056 USA
[5] Univ Illinois, Dept Anim Biol, Urbana, IL 61801 USA
来源
BIOCHIMICA ET BIOPHYSICA ACTA-GENERAL SUBJECTS | 2010年 / 1800卷 / 06期
关键词
Crystallin; Lens; Liquid-liquid phase separation; Transparency; Short-range order; Small-angle X-ray scattering (SAXS); Antarctica; COLLOID-POLYMER SUSPENSIONS; DYNAMIC LIGHT-SCATTERING; AGED ALPHA-CRYSTALLINS; PROTEINS; POLYDISPERSE; EVOLUTION; BETA; TRANSPARENCY; ASSOCIATION; VERTEBRATE;
D O I
10.1016/j.bbagen.2010.02.004
中图分类号
Q5 [生物化学]; Q7 [分子生物学];
学科分类号
071010 ; 081704 ;
摘要
Background: The cortex and nucleus of eye lenses are differentiated by both crystallin protein concentration and relative distribution of three major crystallins (alpha, beta, and gamma). Here, we explore the effects of composition and concentration of crystallins on the microstructure of the intact bovine lens (37 C) along with several lenses from Antarctic fish (-2 degrees C) and subtropical bigeye tuna (18 degrees C). Methods: Our studies are based on small-angle X-ray scattering (SAXS) investigations of the intact lens slices where we study the effect of crystallin composition and concentration on microstructure. Results: We are able to distinguish the nuclear and cortical regions by the development of a characteristic peak in the intensity of scattered X-rays. For both the bovine and fish lenses, the peak corresponds to that expected for dense suspensions of alpha-crystallins. Conclusions: The absence of the scattering peak in the nucleus indicates that there is no characteristic wavelength for density fluctuations in the nucleus although there is liquid-like order in the packing of the different crystallins. The loss in peak is due to increased polydispersity in the sizes of the crystallins and due to the packing of the smaller gamma-crystallins in the void space of a-crystallins. General significance: Our results provide an understanding for the low turbidity of the eye lens that is a mixture of different proteins. This will inform design of optically transparent suspensions that can be used in a number of applications (e.g., artificial liquid lenses) or to better understand human diseases pathologies such as cataract. (C) 2010 Elsevier B.V. All rights reserved.
引用
收藏
页码:556 / 564
页数:9
相关论文
共 56 条
[1]   Quantitative molecular characterization of bovine vitreous and lens with non-invasive dynamic light scattering [J].
Ansari, RR ;
Suh, KI ;
Dunker, S ;
Kitaya, N ;
Sebag, J .
EXPERIMENTAL EYE RESEARCH, 2001, 73 (06) :859-866
[2]   STRUCTURE OF BINARY LIQUID MIXTURES .I. [J].
ASHCROFT, NW ;
LANGRETH, DC .
PHYSICAL REVIEW, 1967, 156 (03) :685-&
[3]   THEORY OF TRANSPARENCY OF EYE [J].
BENEDEK, GB .
APPLIED OPTICS, 1971, 10 (03) :459-&
[4]   Ageing and vision: structure, stability and function of lens crystallins [J].
Bloemendal, H ;
de Jong, W ;
Jaenicke, R ;
Lubsen, NH ;
Slingsby, C ;
Tardieu, A .
PROGRESS IN BIOPHYSICS & MOLECULAR BIOLOGY, 2004, 86 (03) :407-485
[5]  
BLOEMENDAL H, 1986, MOL CELLULAR BIOL EY, P1
[6]   BINARY-LIQUID PHASE-SEPARATION OF LENS PROTEIN SOLUTIONS [J].
BROIDE, ML ;
BERLAND, CR ;
PANDE, J ;
OGUN, OO ;
BENEDEK, GB .
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 1991, 88 (13) :5660-5664
[7]   Evolution of an antifreeze glycoprotein [J].
Cheng, CHC ;
Chen, LB .
NATURE, 1999, 401 (6752) :443-444
[8]   PHYSICOCHEMICAL CHARACTERIZATION OF LENS CRYSTALLINS FROM THE CARP AND BIOCHEMICAL-COMPARISON WITH OTHER VERTEBRATE AND INVERTEBRATE CRYSTALLINS [J].
CHIOU, SH ;
CHANG, WC ;
PAN, FM ;
CHANG, T ;
LO, TB .
JOURNAL OF BIOCHEMISTRY, 1987, 101 (03) :751-759
[9]   Order and disorder in the transparent media of the eye [J].
Clark, JI .
EXPERIMENTAL EYE RESEARCH, 2004, 78 (03) :427-432
[10]  
Dahlman JM, 2005, MOL VIS, V11, P88