The stepwise removal of histones from chicken erythrocyte nucleoprotein

1. A fractionation of chicken erythrocyte histones was achieved simultaneously with their extraction from saline-washed nuclei by stepwise titrations to progressively lower pH values. 2. Different acids and dilute buffer solutions of comparable pH behaved similarly in stepwise extractions of histones. 3. The histone preparations so obtained were characterized by their amino acid composition and behaviour on zone electrophoresis in starch gels. 4. The fractionation by titration was quite sharp at appropriate pH ranges, and the histone fraction that is apparently unique to avian erythrocytes was obtained without contamination by other histone fractions. 5. Histones prepared by stepwise titration were fractionated further by cation-exchange and exclusion chromatography. The chromatographic behaviour and amino acid composition of the components permitted comparison with histones prepared by other methods. 6. Histone fraction IIb was resolved into its subfractions IIb1 and IIb2 by exclusion chromatography on Bio-Gel P-60. 7. Histone fractions III and IV, previously reported to be absent from chicken erythrocyte nuclei, were found in extracts made at pH1.

Download Full-text

The Fractionation of ?-Histones From Chicken Erythrocyte Nuclei

Australian Journal of Biological Sciences ◽

10.1071/bi9641001 ◽

1964 ◽

Vol 17 (4) ◽

pp. 1001 ◽

Cited By ~ 7

Author(s):

JT Bellair ◽

OM Mauritzen

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Gel Electrophoresis ◽

Starch Gel Electrophoresis ◽

Chicken Erythrocyte ◽

Exclusion Chromatography ◽

Starch Gel

Crude IX-histone, obtained from the original histone complex by precipitation of the f3-and y-histones with ethanol, has been shown by starch-gel electrophoresis to contain 13 components. The fractionation of IX-histone by exclusion chromatography on Sephadex G-200 is reported. While none of these components have been obtained pure in the present study, considerable purification of components 2, 3, 4, 5, 8, 9, 10, and 11 has been achieved, and their amino acid composition leaves no doubt that o::-histones represent a muoh larger family of "lysine-rich" proteins than was hitherto supposed.

Download Full-text

Localization and Characterization of the Cleavage-Associated Neoantigen in the Edomain of Fibrinogen

10.1055/s-0039-1680399 ◽

1977 ◽

Author(s):

E. F. Plow ◽

T. S. Edgington

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Conformational Changes ◽

Deae Cellulose ◽

Ion Exchange Chromatography ◽

Exchange Chromatography ◽

Amino Terminal ◽

Exclusion Chromatography

Plasmic cleavage of fibrinogen to generate fragment X partially exposes a specific cryptic molecular site, fg-Eneo. This site in the E domain of the molecule is further exposed during subsequent cleavage. We now report on localization of this site which provides an incisive marker for the structural and conformational changes associated with plasmic cleavage of fibrinogen. Fg-Eneo was stable to reduction and alkylation and the chains of the E fragment were separated by ion exchange chromatography on DEAE-cellulose. An active component was obtained and subjected to molecular exclusion chromatography on Sephadex G-50 to insure removal of intact fg-E. A fg-Eneo positive chain was recovered and identified as Eγ with respect to amino-terminal tyrosine, amino acid composition, and immunochemical analysis. The fg-Eneo site was stable to tryptic degradation, and tryptic peptides were prepared and separated by multiple molecular exclusion chromatographic steps. Final separation of two peptides of similar size was achieved on the basis of carbohydrate content by affinity chromatography on Concanavalin A. Only the active peptide was bound by the lectin. Purity and identification of the active tryptic peptide as γ36–53 was established by amino acid composition and sequence. These results establish that this region of the γ chain of fibrinogen is not present at the hydrated surface of the native molecule but that, in association with plasmic cleavage and conformational changes, this site is progressively exposed and provides a dynamic marker of the cleavage sequence.

Download Full-text

Dissociation of ϰ- and λ-chains from reduced human immunoglobulins

Biochemical Journal ◽

10.1042/bj0970460 ◽

1965 ◽

Vol 97 (2) ◽

pp. 460-465 ◽

Cited By ~ 26

Author(s):

S Cohen ◽

S Gordon

Keyword(s):

Amino Acid ◽

Amino Acid Composition ◽

Acid Composition ◽

Light Chain ◽

Human Immunoglobulin ◽

Light Chains ◽

Type K ◽

Human Immunoglobulins ◽

Starch Gels ◽

Bence Jones Proteins

1. The light chains of human immunoglobulin (Ig) exist in two forms, kappa (type K) and lambda (type L). The two types of chains can be partially separated by taking advantage of the fact that lambda-chains, for the most part, dissociate from reduced Ig at higher pH than do the kappa-chains. The same difference in dissociation of type K and L chains was observed with myeloma IgG and IgA proteins, but not with pathological IgM proteins. 2. When analysed in urea-glycine starch gels, pH7, both kappa- and lambda-chains show ten electrophoretic bands having the same mobilities as those of the whole light-chain subfractions. Normal kappa- and lambda-chains show similar differences in overall amino acid composition to those previously found with myeloma kappa- and lambda-chains and type K and L Bence-Jones proteins.

Download Full-text