Beta Crystallin S

Crystallins are group of structural water soluble proteins that constitute 90% of the vertebrate lens.  There are 4 distinct classes of crystallins, alfa-, beta-, gamma- and delta-crystallins. The mammalian lens does not express delta-crystallins and it confined to birds lens.  The human eye lenses at birth contain at least 14 distinct lenses specific proteins called crystallins, 12 of which are full length proteins are 2 are truncated ranging in molecular weight from 20-30 kDa.  The relative proportional expression of alfa and beta crystallins in human eye lenses during the 2-300 days is in integral proportion indicating a molar relation ship between these proteins.  During early development the ratios of alfaA and beta B2 crystallin change proportionally to the logrithm of age during the first year with alfa A decreasing and beta B2 decreasing in equimolar ratios.  Though the functional significance of the reciprocal decrease in alfaA and an increase in betaB2 is not fully known, the beta crystalline may be substituting the alfa crystalline in later part of life (1).   Two major determinants of the transparency of the lens are protein-protein interactions and stability of the crystallins, the structural proteins in the lens. betaB2 is the most abundant beta-crystallin in the human lens and is important in formation of the complex interactions of lens crystallins.  Certain post transaltional modifications and formation of homo and heterodimers also pay an in important role in the over all transparency of the eye lenses.  The thermodynamic and kinetic stabilities of the eye lens proteins, beta-gamma-crystallins are important in the etiology of senile cataract by controlling the chance of proteins unfolding, which can lead to aggregation and loss of transparency. betaB2-Crystallin orthologs are of low stability and comprise two typical beta-gamma-crystallin domains, although, uniquely, the N-terminal domain has a cysteine in one of the conserved folded beta-hairpins.  Most of crystalline genes are located on the human chromosome 2 except gamma S crystalline, located on chromosome 3. 

Numerous post-translational changes take place in crystalline popylpeptide including deamidation, cleavage, oxidation, during maturation and ageing of the lens.  The nucleotide sequence of the cDNA of eye lens beta s-crystallin has been determined and the amino acid sequence has been confirmed by amino acid compositions and partial sequences of the tryptic peptides of this monomeric protein. beta s-Crystallin has a length of 178 residues, corresponding to a mol. wt. of 21 kDa.  The crystalline S has a blocked N-terminal serine. Comparison of beta s with the known sequences of other beta- and gamma-crystallins shows beta s to be more closely related to the monomeric gamma-crystallins than to the oligomeric beta-crystallins. The computer assisted molecular modeling of beta S crystallin suggested similarities with the gamma-crystallins which supports its monomeric behavior (3).  The water soluble beta crystalline S also are substrate for lens transglutaminase which catalyze the formation of epsilon and gamma glutamyl-lysine isopeptides cross links between polypeptides (3). 

The anti-beta S crystalline antibodies were generated using cyclic peptide methodology. The anti-crystallin S antibodies are generated in rabbits using KLH conjugated immunogenic peptides representing two distinct epitopes on the beta crystalline S protein.  The antibodies were affinity purified and stabilized in our proprietary formulated antibody stabilization buffer.  FabGennix International Inc., will conjugate these antibodies to fluorophores or secondary enzymes for a nominal charge.  Western blot positive controls (PC-BxtlS) in ready-to-use buffer is available for this antibody.  Limited quantities of antigenic blocking peptides are also available.  FabGennix International Inc., has made a number of antibodies related to eye research, for a complete listing please visit www.fabgennix.com.

For research use only, not for diagnostic or therapeutic use.