STUDIES ON LENS PROTEINS .1. SUBUNIT STRUCTURE OF BETA CRYSTALLINS OF RABBIT LENS CORTEX

  • 1 January 1978
    • journal article
    • research article
    • Vol. 17  (7) , 660-666
Abstract
A method was developed to isolate and characterize .beta.-crystallins of rabbit lens cortex. Chromatographic separation of water-soluble structural proteins of rabbit lens cortex on a Sephacryl S-200 gel column yielded four .beta.-crystallin peaks (.beta.1, .beta.2 .beta.3 and .beta.4), all eluting between .alpha.- and .gamma.-crystallins. Their MW were estimated to be 250,000, 130,000, 60,000 and 37,000 daltons, respectively. SDS[Sodium dodecylsulfate]-gradient gel electrophoresis of these .beta.-crystallins gave rise to characteristic polypeptides; .beta.1, 2 polypeptides of 30,000 and 23,000 daltons; .beta.2, 1 major polypeptide of 33,000; .beta.3, 2 polypeptides of 28,000 and 26,000; and .beta.4, 2 polypeptides of 22,500 and 11,200 daltons. From a knowledge of the MW and the ratio of the polypeptides in each crystallin, their oligomeric structure was 5:5, 4, 1:1 and 1:1. The relative abundance of these four .beta.-crystallins was 25.6, 7.2, 27.7 and 2.8% of the total water-soluble proteins of the lens cortex.