Genetic polymorphism of erythrocyte histone H1 in Japanese quail

Resolution of allelic and non-allelic variants of histone H1 by cation-exchange-hydrophilic-interaction chromatography

A mixed-mode high-performance liquid chromatography (HPLC) method that resolves the six known non-allelic variants of chicken erythrocyte histone H1 is described. Common, but previously unknown, allelic variants of H1 that comigrate in polyacrylamide gel electrophoresis are also resolved. The resolution of H1 variants achieved by this method should be useful in determining the functional significance of H1 sequence heterogeneity and in analyses of post-translational modification of H1. Furthermore, the principles behind the separation should be applicable to analyses of polymorphism in other proteins.

Capillary electrophoresis of histone H1 variants at neutral pH in dynamically modified fused- silica tubing

Existing methods for the analysis of histone H1 by capillary electrophoresis (CE) employ acidic buffers (pH <3.0) to suppress silanol ionization and minimize the loss of these extremely basic proteins by adsorption to capillary walls. Here we describe the use of Polybrene (PB) as a dynamic modification reagent in a simple procedure that facilitates the analysis of chicken H1 at neutral pH. PB is adsorbed to the inner surfaces of capillaries to render them cationic prior to use and a low concentration of PB is included in the electrolyte to replenish the coating during use. Inclusion of ethylenediaminetetraacetic acid (EDTA) in the electrolyte results in the assembly of a dynamic cation-exchange layer upon the immobilized PB that influences the relative mobilities of H1 variants. The six nonallelic variants of H1 known in this species as well as certain allelic variants are resolved. Because the procedure is effective in preventing the adsorption of proteins as basic as H1 at neutral pH, this strategy should facilitate CE analyses of many basic proteins under conditions that maintain their native conformation.

Natural allelic variation of duck erythrocyte histone H1b

In our previous work (J. Palyga, Genetic polymorphisms of histone H1. b in duck erythrocytes. Hereditas 114, 85-89, 1991) we reported a genetic polymorphism of duck erythrocyte histone H1.b. Here, we screened H1 preparations in a two-dimensional polyacrylamide gel to refine the distribution of allelic forms of H1.b in fifteen duck populations. We have revealed that the frequency of H1.b allelic variants was significantly different among many conservative and breeding duck groups. While b(1) and b(3) were common in all populations screened, the allele b(2), with a slightly lower apparent molecular weight, was confined mainly to brown-feathered ducks (Khaki Campbell and Orpington) and descendent lines. The C- and N-terminal peptides released upon cleavage with N-bromosuccinimide and Staphylococcus aureus protease V8 from duck allelic histones H1. b2 and H1.b3, respectively, migrated differently in the gel, probably as a result of potential amino acid variation in a C-terminal domain.

The occurrence of a mutant dimerizable histone H5 in Japanese quail erythrocytes

An allelic variant of linker histone H5 has been found in the erythrocytes of Japanese quail (Coturnix japonica) descended from a small group of feral birds captured on the island of Hawaii. This variant spontaneously forms protein dimers in vitro in the absence of reducing agents. That this depends upon the introduction of a sulfhydryl group (presumably because of a cysteine substitution) is indicated by its reaction with 2-nitro-5-thiocyanobenzoate and by its fluorescence after reaction with 4-aminosulfonyl-7-fluoro-2,1,3-benzoxadiazole. This is the first reported example of cysteine in a vertebrate linker histone and offers a specific reactive site for structural studies. A homozygous line for this form of H5 is being developed.

Genetic polymorphism of histone H1.z in duck erythrocytes

Three different phenotypes of erythrocyte histone H1.z were detected in several lines of duck by using two-dimensional PAGE. Electrophoresis and inheritance data have shown that two co-dominant alleles, z1 and z2, encode two proteins which differ slightly in their apparent molecular masses. Allele z1 was very abundant and was found at a frequency at least 0.94, while allele z2 was very rare and was present at a frequency of less than 0.06. Limited chemical and enzymic cleavages appeared to indicate that the allelic forms of histone H1.z differed in the C-terminal regions of their molecules.