Search Results

You are looking at 1 - 8 of 8 items for

  • Author: P. A. BRIGGS x
Clear All Modify Search
Free access

J. C. BOURSNELL and P. A. BRIGGS

Summary.

The haemagglutinating protein (or proteins) have been separated from boar seminal plasma largely by gel filtration methods. Electrophoretic studies have shown that the haemagglutinating protein material (now designated Protein H) is positively charged and that it possesses an isoelectric point (i.e.p.) of about 9·4. Earlier electrophoretic observations on mixtures of boar seminal plasma proteins have been verified with the greatly purified Protein A (i.e.p. 8·8) and Protein B (i.e.p. 4·6). It has been possible to explain some hitherto puzzling properties of the boar seminal plasma caused by isolation of various combinations of Protein A, Protein B and Protein H.

Free access

J. C. BOURSNELL, D. M. COLE and P. A. BRIGGS

Summary.

Separation of the haemagglutinating protein from other boar seminal plasma proteins has been achieved by using gel-filtration methods. The protein is coagulated by heating at 100° C for 15 min at pH 8·2. It has been confirmed that the haemagglutinating protein thus separated causes the precipitation of Fraction B at pH 8 and low ionic strength. The coagulation by heating of the Fraction A protein of boar seminal plasma has been further studied.

Free access

U. LAVON, J. C. BOURSNELL and P. A. BRIGGS

In an earlier study on the characteristics of boar seminal plasma (Boursnell, Nelson & Cole, 1966), use was made of ultrafiltrates, though this did not include an investigation of the ultrafiltered proteins. Recently, preliminary determinations have shown that the ultrafiltrate contains 4% of the seminal plasma protein and is devoid of the haemagglutinating protein H (Boursnell & Briggs, 1969).

In a further study of the nature of this protein material, isoelectric focusing on polyacrylamide plates was used. Comparisons of this material were made with whole seminal plasma, seminal plasma from which the haemagglutinin was absorbed with washed bull spermatozoa (Boursnell, 1967) and with proteins `A Seph' and `A Dial' prepared from boar seminal plasma as described by Boursnell et al. (1966). `A Seph' should contain the haemagglutinin and `A Dial' should lack it (Boursnell

Free access

J. C. BOURSNELL, P. A. BRIGGS and D. M. COLE

Summary.

Further studies, using gel filtration on Sephadex G-200 columns, have confirmed and extended the similarities between the major proteins of boar seminal plasma and the vesicular secretion.

The haemagglutinin in the vesicular secretion has been shown, by red cell agglutination, to occur as a distinct peak masked by the greater protein content of Fraction A.

Completely fresh vesicular secretion kept at 37° C and studied at this temperature within 30 min of slaughter, presents an identical gel filtration pattern.

Free access

U. LAVON, P. A. BRIGGS and J. C. BOURSNELL

Summary.

The protein patterns of boar seminal plasma, vesicular secretion and epididymal plasma and of their fractions obtained by gel filtration and dialysis were further studied by gel disc electrophoresis and isoelectric focusing on polyacrylamide.

The majority of the seminal plasma proteins originate in the seminal vesicles and the quantitative contribution of the epididymides to the protein pattern is small. Proteins A, B and H were found to be mixtures of large numbers of proteins which were identified and characterized.

Free access

J. C. BOURSNELL, P. A. BRIGGS, U. LAVON and E. J. BUTLER

Summary.

Ultrafiltration studies strengthen the suggestion that zinc in boar seminal plasma and vesicular secretion is partitioned between high and low molecular weight ligands. Studies employing graded ethanol precipitation of seminal plasma proteins failed to reveal the presence of a zinc-rich protein.

Free access

J. C. BOURSNELL, P. A. BRIGGS, U. LAVON and E. J. BUTLER

Summary.

Gel-filtration and dialysis studies on the state of zinc in boar seminal plasma and vesicular secretion strongly suggest that the zinc is partitioned between two or more ligands of which the most likely are proteins and citrate. This partition is very sensitive to changes in pH and buffer composition and an increasing proportion of the zinc is precipitated at pH values above 7. No firmly bound protein-zinc complex was found which could account for the close correlation between the zinc and protein nitrogen contents previously observed for these fluids.

Free access

J. C. BOURSNELL, S. BARONOS, P. A. BRIGGS and E. J. BUTLER

Summary.

Forty-five samples of seminal plasma obtained from eight boars and seventeen samples of vesicular secretion collected from individual boars had mean zinc contents of 22·7 and 137·4 μg/ml, respectively. It was concluded that most of the zinc present in the seminal plasma of the boar is derived from the vesicular secretion.

The mean concentrations of the organic constituents studied were:

Seminal plasma: total nitrogen 4·42 mg/ml (non-dialysable 88·7%), citrate 1·28 mg/ml.

Vesicular secretion: total nitrogen 15·1 mg/ml (non-dialysable 93·9%), citrate 6·07 mg/ml, fructose 0·557 mg/ml, galactose 0·092 mg/ml.

In both seminal plasma and vesicular secretion, the concentration of zinc was positively correlated with that of total and non-dialysable nitrogen and citrate. The correlation with nitrogenous substances was particularly strong in the seminal plasma of individual animals and there was evidence from the partial correlation coefficients that these associations were independent of the zinc-citrate relationship. However, fructose and galactose which do not have an appreciable affinity for zinc under physiological conditions also showed significant positive correlations with zinc (in vesicular secretion) and most of the organic constituents were interrelated in this way, indicating that in such data the influence of chemical combination may be masked by that of other factors which regulate the composition of these fluids.