Biomaterial Database

[A 35-kDa polypeptide of the crystalline lens in the common frog: its biochemical properties, tissue specificity and appearance in the developmental process]. 1990

V N Simirskiĭ, and K S Aleĭnikova, and A T Mikhaĭlov

The vertebrate lens contains so-called taxon-specific water-soluble proteins. One of them is p-crystallin with a molecular weight of 35 kDa characteristic of Ranidae family. We have identified a polypeptide with a molecular weight of 35 kDa in the eye lens of Rana temporaria which: (1) can be extracted from the lens by aqueous salt solutions, (2) has a molecular mass of 36.1 +/- 0.4 kDa (by SDS-electrophoresis) and 37 kDa (by gel filtration), (3) is heterogeneous in terms of isoelectric point (pI 6.5-8.0), (4) binds to heparin-agarose, (5) denatures in response to freezing-thawing, lyophilization and in solutions with low ionic strength. Thus, major biochemical parameters of this polypeptide differ from that of amphibian alpha, beta- and gamma-crystallins. In addition to lens, 35 kDa polypeptide was detected by immunoelectroblotting in retina, testes, liver, kidney, spleen, stomach, intestine and lungs. Its level (as percentage of water-soluble protein) is 1.1 +/- 1.4% in the lens, 1.6 +/- 0.7% in retina. 0.05% in testes and liver and 0.01% or less in other organs. Thus, despite its wide tissue distribution, 53 kDa polypeptide is expressed predominantly in lens and retina. We studied the time-course of appearance and accumulation of this polypeptide in tissues where it is expressed at high or low levels. 35 kDa polypeptide was detected for the first time during larval development: (1) in the lens (some time after the mouth opening; stages 33-34 according to Dabagian and Sleptsova, 1975), (2) in the retina (by the time of anus opening; stages 36-37), (3) in the liver (at the stage of elongated hind limb bud; stages 40-41). Definitive expression level of this protein was achieved in the lens by the beginning of metamorphosis and in the retina and liver during first months of development. Hence, during the whole period of larval development 35 kDa polypeptide content of the lens exceeds that of retina or liver. A more substantial evidence is required to confirm the identity of studied polypeptide with rho-crystallin.

UI	MeSH Term	Description	Entries
D007120	Immunochemistry	Field of chemistry that pertains to immunological phenomena and the study of chemical reactions related to antigen stimulation of tissues. It includes physicochemical interactions between antigens and antibodies.
D007814	Larva	Wormlike or grublike stage, following the egg in the life cycle of insects, worms, and other metamorphosing animals.	Maggots,Tadpoles,Larvae,Maggot,Tadpole
D007908	Lens, Crystalline	A transparent, biconvex structure of the EYE, enclosed in a capsule and situated behind the IRIS and in front of the vitreous humor (VITREOUS BODY). It is slightly overlapped at its margin by the ciliary processes. Adaptation by the CILIARY BODY is crucial for OCULAR ACCOMMODATION.	Eye Lens,Lens, Eye,Crystalline Lens
D008970	Molecular Weight	The sum of the weight of all the atoms in a molecule.	Molecular Weights,Weight, Molecular,Weights, Molecular
D009024	Morphogenesis	The development of anatomical structures to create the form of a single- or multi-cell organism. Morphogenesis provides form changes of a part, parts, or the whole organism.
D009928	Organ Specificity	Characteristic restricted to a particular organ of the body, such as a cell type, metabolic response or expression of a particular protein or antigen.	Tissue Specificity,Organ Specificities,Specificities, Organ,Specificities, Tissue,Specificity, Organ,Specificity, Tissue,Tissue Specificities
D010455	Peptides	Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are considered to be larger versions of peptides that can form into complex structures such as ENZYMES and RECEPTORS.	Peptide,Polypeptide,Polypeptides
D011896	Rana temporaria	A species of the family Ranidae occurring in a wide variety of habitats from within the Arctic Circle to South Africa, Australia, etc.	European Common Frog,Frog, Common European,Common European Frog,Common Frog, European,European Frog, Common,Frog, European Common
D003459	Crystallins	A heterogeneous family of water-soluble structural proteins found in cells of the vertebrate lens. The presence of these proteins accounts for the transparency of the lens. The family is composed of four major groups, alpha, beta, gamma, and delta, and several minor groups, which are classed on the basis of size, charge, immunological properties, and vertebrate source. Alpha, beta, and delta crystallins occur in avian and reptilian lenses, while alpha, beta, and gamma crystallins occur in all other lenses.	Lens Proteins,Crystallin,Eye Lens Protein,Lens Protein, Eye,Protein, Eye Lens,Proteins, Lens
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia