ISOLATION, PURIFICATION, AND CHARACTERIZATION OF γ-LIPOTROPIC HORMONE FROM SHEEP PITUITARY GLANDS

The isolation and characterization of a new biologically active polypeptide from sheep pituitary glands is described. Considerable evidence suggests that the structure of the new molecule, designated γ-lipotropin, is identical with the N-terminal portion (sequence 1–58) of β-lipotropin and, therefore, that γ-lipotropin contains at its C-terminus the amino acid sequence of β-melanophore-stirnulating hormone (β-MSH). The implications of these results are discussed in relation to the mechanism of pituitary peptide biosynthesis and to the structure–activity relationships between sheep β-MSH and lipotropic hormones.

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Purification and characterization of biologically active 1,4-linked α-d-oligogalacturonides after partial digestion of polygalacturonic acid with endopolygalacturonase

Carbohydrate Research ◽

10.1016/0008-6215(93)84237-z ◽

1993 ◽

Vol 247 ◽

pp. 9-20 ◽

Cited By ~ 58

Author(s):

Mark D. Spiro ◽

Keith A. Kates ◽

Alan L. Koller ◽

Malcolm A. O'Neill ◽

Peter Albersheim ◽

...

Keyword(s):

Biologically Active ◽

Polygalacturonic Acid ◽

Purification And Characterization ◽

Partial Digestion

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STUDIES ON ACTH-BINDING ANTIBODIES: CHARACTERIZATION OF IMMUNOLOGICAL SPECIFICITIES

Acta Endocrinologica ◽

10.1530/acta.0.0620521 ◽

1969 ◽

Vol 62 (3) ◽

pp. 521-536 ◽

Cited By ~ 7

Author(s):

M. L. Aubert ◽

J.-P. Felber

Keyword(s):

Binding Sites ◽

Competitive Inhibition ◽

Biologically Active ◽

Active Part ◽

Terminal Portion ◽

Plasma Acth ◽

Acth Fragments ◽

Selection Of

ABSTRACT In investigations on the production and the specificity of anti-ACTH antibodies used for radioimmunoassay, differences have been observed between the various antibodies obtained. It was shown by means of competitive inhibition with different ACTH fragments that the binding of the ACTH molecule to its antibody can occur at different sites along the ACTH peptide. By varying the concentrations of the fragments and the conditions of the assays, it was possible to study the properties of each antibody. Thus antibodies which bind the N-terminal portion, or which exclusively bind the biologically active part of the ACTH chain (1–20), are the most suitable for radioimmunoassay. It was found, however, that the production of antiserum was generally more frequent when binding occurred to the C-terminal portion of the ACTH peptide. Should the presence of such fragments in plasma be confirmed, then the use of these antisera could lead to erroneous measurement of biologically inactive ACTH fragments. Thus, this study reveals that a selection of the antibody for specificity might be necessary for its application to the radioimmunoassay of plasma ACTH, and that this selection could be performed with the use of ACTH fragments. An approach to the problem of binding sites between antigen and antibody has been described and the possibility of introducing a radioimmunoassay for plasma ACTH fragments discussed.

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Purification and characterization of tuberculin-active components from BCG

Canadian Journal of Microbiology ◽

10.1139/m75-290 ◽

1975 ◽

Vol 21 (12) ◽

pp. 2019-2027

Author(s):

M. Laguerre ◽

R. Turcotte

Keyword(s):

Physicochemical Properties ◽

Guinea Pigs ◽

Gel Filtration ◽

Biologically Active ◽

Polyacrylamide Gels ◽

Active Components ◽

Purification And Characterization ◽

Molecular Weights ◽

Antigenic Activity

The tuberculin activity of protoplasmic extracts isolated from living BCG was purified successively by gel filtration on Sephadex G-100 and G-75, and by electrophoresis on 7.5% and on gradient (6–18%) polyacrylamide gels. The tuberculin-active fractions, as determined in BCG-sensitized guinea pigs, were used as the starting material for each of the following fractionation steps.The physicochemical properties and the antigenic activity of the biologically active fractions have shown that a single component, or only a few ones with similar properties, possessed high tuberculin activity. These active components were proteins having relatively high molecular weights (about 72 000) and could behave as antigens.

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