scholarly journals Two-step affinity-chromatographic purification of cathepsin D from pig myometrium with high yield

1981 ◽  
Vol 197 (2) ◽  
pp. 519-522 ◽  
Author(s):  
E G Afting ◽  
M L Recker

Cathepsin D was purified by two-step affinity chromatography on concanavalin A- and pepstatin-Sepharose. The main purification was achieved by washing the enzyme bound to the pepstatin-Sepharose column with buffered 6 M-urea. This step separated cathepsin D from all low- and high-molecular-weight impurities. Although the 1700-fold purified acid proteinase was homogeneous on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, it still showed microheterogeneity.

1976 ◽  
Vol 159 (1) ◽  
pp. 181-184 ◽  
Author(s):  
N Paskin ◽  
R J Mayer

Fatty acid synthetase purified from the mammary gland of the rabbit has a mol. wt. of 968000 as determined by gel filtration. The enzyme gave one band, corresponding to a mol.wt. of approx. 35000, on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate and phenylmethanesulphonyl fluoride.


1984 ◽  
Vol 44 (2) ◽  
pp. 117-123 ◽  
Author(s):  
N. K. Singh ◽  
K. W. Shepherd

SUMMARYThe gene(s) controlling the high-molecular-weight glutelin subunits in rye (designated as Glu-Rl) was mapped with respect to the centromere using a 1RL-1DS wheat-rye translocation line and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Analysis of 479 seeds from test-crosses between a 1R/1RL-1DS heterozygote and the cultivar India 115, revealed 14·6% aneuploid and 3·95% recombinant progeny. Excluding the aneuploids, this locus was calculated to be 4·65 ± 1·04 cM from the centromere on the long arm of chromosome 1R, which is comparable to the position of the homoeologous loci in wheat and barley.


1977 ◽  
Vol 167 (2) ◽  
pp. 509-512 ◽  
Author(s):  
C W Bamforth ◽  
P J Large

N-Methylglutamate dehydrogenase, purified to a specific activity of 0.29 unit/mg of protein, gave one band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, corresponding to a molecular weight of 130 000. Enzyme-Triton complexes were found to have a partial specific volume of 0.73 cm3/g, suggesting that the protein binds less than 0.1 g of Triton/g of protein. A molecular weight for the intact enzyme in the presence of 1% (w/v) Triton X-100 of 550 000 suggested that the enzyme may be a tetramer.


1980 ◽  
Vol 185 (1) ◽  
pp. 227-237 ◽  
Author(s):  
Y Nagamatsu ◽  
T Oka

alpha-Lactalbumin was purified to apparent homogeneity from mouse milk by combined use of gel filtration, chromatography on DEAE-cellulose and hydroxyapatite, and concanavalin A-Sepharose affinity chromatography. Mouse alpha-lactalbumin exists in several species with different charges and in two molecular-size forms. The smaller form, which constituted over 90% of total alpha-lactalbumin, included two major and two minor species, each of which showed different electrophoretic mobility on polyacrylamide-gel electrophoresis, but gave the same single band on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis in two different buffer systems and over the range 10-15% acrylamide concentrations. The molecular weight was estimated as 14 100. The two major species of the smaller form had the same amino acid composition and contained no significant amount of carbohydrate. The larger form of alpha-lactalbumin, consisting of two species with different charges, was present in a small amount (less than 10%) in the milk and was isolated by its ability to interact with concanavalin A-Sepharose. Each of the two species also gave the same single band of apparent mol.w.t 18 500 on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. However, this value may be anomalous, since this larger form appears to be glycosylated, and glycoproteins can behave anomalously on sodium dodecyl sulphate/polyacrylamide gels by binding less sodium dodecyl sulphate. All species of mouse alpha-lactalbumin from milk were active in the lactose synthase reaction and showed identical immunological properties, as determined by the mono-specific antibody prepared against the small major species. The presence of both the larger and the smaller forms, each in a percentage concentration similar to that found in milk, was also demonstrated in alpha-lactalbumin induced by hormones in organ cultureof pregnant-mouse mammary gland.


1981 ◽  
Vol 193 (2) ◽  
pp. 621-629 ◽  
Author(s):  
K Yonemasu ◽  
T Sasaki

1. Mouse C1q, a subcomponent of the first component of complement, has been purified in a highly haemolytically active form by a combination of precipitation with EGTA, ion-exchange chromatography and gel filtration. Yields ranged from 3 to 5 mg/200 ml of serum, and the activity of final preparations was in the range of 2 × 10(13)-4 × 10(13) C1q effective molecules/mg. 2. The molecular weight of mouse C1q was 439 500 +/- 1586, as determined by polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate. 3. Mouse C1q was shown to be composed of non-covalently linked subunits, all being in the molecular-weight range 45 000-46 000, and three covalently linked chains each having a molecular weight of approx. 23 000 as determined on polyacrylamide-gel electrophoresis in the presence of sodium dodecyl sulphate by using non-covalently and covalently linked subunits of human C1q as markers with known molecular weights calculated theoretically previously [Porter & Reid (1978) Nature (London) 275, 699-704]. 4. Mouse C1q contained hydroxyproline, hydroxylysine, a high percentage of glycine and approx. 9% carbohydrate. The absorption coefficient and nitrogen content of C1q were also determined.


1983 ◽  
Vol 211 (2) ◽  
pp. 397-404 ◽  
Author(s):  
L Heickendorff ◽  
T Ledet

Arterial basement-membrane-like material was isolated from rabbit aortic myomedial cell cultures by sonication and differential centrifugation. Isolated basement-membrane-like material was shown to be free of both cellular and matrix contaminants, on the basis of determinations of DNA, RNA, cholesterol, phosphorus and (Na+ + K+)-activated ATPase, combined with electron microscopy. Amino acid analyses showed that arterial basement-membrane-like material was composed of predominantly non-collagenous amino acids. Evaluated by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, reduced basement-membrane-like material comprised six major and about 30 minor components in the Mr range 10 000-600 000. One of the major peptides (Mr 225 000) was disulphide-linked. Periodic acid-Schiff staining of gels indicated that most high-molecular-weight components were glycoproteins. Two-dimensional gel electrophoresis resolved reduced basement-membrane-like material into more than 100 components, with pI from 5 to 7. The disulphide-linked Mr-225 000 peptide appeared heterogeneous, with pI of 5.6-6.0, and was considered to represent fibronectin. All major peptides were of non-collagenous nature, on the basis of their susceptibility to pepsin and resistance to collagenase. Purified myomedial basement-membrane-like material contained collagenous peptides, as indicated by the presence of hydroxyproline and hydroxylysine. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis of pepsin-treated and reduced basement-membrane-like material revealed five high-molecular-weight collagenous components appearing in the Mr range 105 000-375 000 relative to type I collagen standards.


1986 ◽  
Vol 53 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Lesley C. Chaplin ◽  
Richard L. J. Lyster

SUMMARYThe irreversible heat denaturation of α-lactalbumin (α-la) in 0·1 M-phosphate, pH 7·0, at 100 °C was studied using polyacrylamide-gel electrophoresis (PAGE). PAGE revealed two groups of bands, one moving faster than native α-la and one slower, in addition to some denatured protein which remained at the origin and some residual native α-la. The faster group had unchanged molecular weight, but an increase in charge, partly due to hydrolysis of glutamine and asparagine residues. The slower group was shown by two-dimensional sodium dodecyl sulphate-PAGE to be oligomers of denatured α-la; formation of the smaller oligomers preceded the larger ones. The oligomers reverted to monomers in the presence of dithiothreitol, showing that they were disulphide-linked aggregates of denatured α-la. Immuno-blots of the gels showed that both fast and slow groups of bands had irreversibly lost most of the antigenicity of the native protein.


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