scholarly journals Molecular properties of lupin and serradella leghaemoglobins

1972 ◽  
Vol 127 (1) ◽  
pp. 309-314 ◽  
Author(s):  
W. J. Broughton ◽  
M. J. Dilworth ◽  
C. A. Godfrey

1. Leghaemoglobins were extracted from the root nodules of lupin (Lupinus luteus L.) and serradella (Ornithopus sativus Brot.) plants and fractionated into different leghaemoglobin components on DEAE-cellulose–acetate columns. 2. The first two fractions eluted from columns loaded with either lupin or serradella leghaemoglobins were in the Fe3+ oxidation state. 3. These components have protohaem IX as the prosthetic group and glycine as the N-terminal amino acid. 4. Other properties are: lupin component I, pI5.08, molecular weight 19000; lupin component II, pI5.13, molecular weight 20600; serradella component I, pI5.00, molecular weight 17500; serradella component II, pI5.05, molecular weight 19100. 5. Leghaemoglobins are thus heterogeneous with respect to size and charge.

1975 ◽  
Author(s):  
A.D. Muller ◽  
B. M. Bas ◽  
H. C. Hemker

Staphylocoagulase, an exoprotein of coagulase positive staphylocoagulase, has been purified to a state in which only trace amounts of contaminating proteins are detectable.Purification was more than 35,000 fold, which is 7 times more than the highest value reported in the literature. The yield was about 15%.Aspartic acid was found as a single N-terminal amino acid in this preparation. The molecular weight is 61,000 and the isoelectric point lies at pH 4.53.The amino acid composition was determined.


1968 ◽  
Vol 23 (11) ◽  
pp. 1412-1426 ◽  
Author(s):  
H. D. Schlumberger

Purification of commercially available HCG preparations with DEAE Sephadex A 50 and Sephadex G 100 column chromatography gave homogeneous fractions having specific biological activities four fold those of the starting materials. The purified HCG has ICSH characteristics and, in high doses, a definite FSH effect is present.Chemical analysis of HCG showed it to contain 29% carbohydrates and 69% peptides. The C-terminal amino acid of the peptide chain was found to be serine, but the N-terminal amino acid could not be determined with normal methods. A molecular weight of 22000 — 27000 daltons was obtained by quantitative end group analysis. Ultracentrifugation experiments in 4 m guanidine hydrochloride gave a molecular weight of 27200 daltons, but in neutral saline solutions at HCG concentrations above 2 mg/ml the apparent molecular weight was higher and indicated dimer formation. A dissociation constant of 10-5 mol/l was estimated for the monomer-dimer equilibrium. Since biological activity is found with 0.1 to 0.5 µg, it was concluded that the HCG monomer is the active entity.The purified HCG is stable from pH 4.5 to pH 10 for 6 hours at 37 °C. At pH 2.5 only 5 to 10% of the original activity is retained. HCG is rapidly inactivated at 100 °C, but a residual activity of 6 — 10% remained after 30 minutes at 80 °C. No activity was lost after 30 minutes incubation at 60 °C.


1991 ◽  
Vol 130 (2) ◽  
pp. R1-R4 ◽  
Author(s):  
J. L. Vallet ◽  
P. J. Barker ◽  
G. E. Lamming ◽  
N. Skinner ◽  
N. S. Huskisson

ABSTRACT Ovine trophoblast protein-1 (oTP-1), stimulates the secretion of several proteins in explant culture of day-12 cyclic ovine endometrium. We partially purified and identified one of these proteins, an 11,000 Mr, pI approx. 6 protein by N-terminal amino acid sequencing and immunoprecipitation using antibody to human β2-microglobulin. The protein was purified from cultures of endometrium collected from day-16 pregnant ewes. The N-terminal amino acid sequence was 40–55% homologous to β2-microglobulin from a variety of species. Antibody to human β2-microglobulin immunoprecipitated the protein and another protein of similar molecular weight but more acidic pi. Using immunoprecipitation of radiolabelled proteins from culture, we demonstrated that oTP-1 increased production of this protein by 40% (P<0.05). We conclude that oTP-1 increases the secretion of a β2-microglobulin-like protein from day-12 non-pregnant endometrium in culture.


1970 ◽  
Vol 48 (9) ◽  
pp. 1017-1021 ◽  
Author(s):  
C. Gilardeau ◽  
M. Chrétien

A lipolytic substance was isolated from porcine pituitary glands. It's amino acid composition, molecular weight, N-terminal amino acid, isoelectric point, and biological activities are reported. These results are compared to the corresponding values of sheep β-lipolytic hormone.


1973 ◽  
Vol 51 (9) ◽  
pp. 1229-1239 ◽  
Author(s):  
Surinder Cheema ◽  
S. J. Soldin ◽  
Antoinetta Knapp ◽  
T. Hofmann ◽  
K. G. Scrimgeour

Quinonoid dihydropterin reductase has been purified to homogeneity from sheep liver, sheep brain, and beef adrenal medulla. Each of these enzymes has a molecular weight of about 45 000–55 000, and is composed of two subunits of half that weight. The subunits of the sheep liver reductase have identical charge, size, and N-terminal amino acid residue. The reductase exists in solution over a wide range of concentrations as the dimer. A dimer covalently linked by dimethylsuberimidate retains full activity. A number of kinetic properties of quinonoid dihydropterin reductase, including inhibition by thiol reagents and by pterin analogues, are reported.


1975 ◽  
Vol 145 (3) ◽  
pp. 459-467 ◽  
Author(s):  
D Parris ◽  
L S Swart

The complete amino acid sequence of mohair protein, SCMKB-M1.2 (97 residues), was determined. The protein was isolated from reduced and carboxymethylated mohair by chromatography on DEAE-cellulose phosphate. Peptides for sequence determination were obtained by digestion with trypsin, pepsin, chymotrypsin, thermolysin and papain, and were fractionated by DEAE-cellulose chromatography, paper chromatography and electrophoresis. The sequence of the peptides were determined by the Edman degradation method (by use of both the Beckman Sequence and a non-automatic procedure), and by partial acid hydrolysis. The protein is closely homologous to wool protein SCMKB-IIIB2, and also contains acetylated alanine as N-terminal amino acid.


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