scholarly journals Arterial basement-membrane-like material isolated and characterized from rabbit aortic myomedial cells in culture

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.

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.


1981 ◽  
Vol 195 (2) ◽  
pp. 389-397 ◽  
Author(s):  
D A Wiginton ◽  
M S Coleman ◽  
J J Hutton

Adenosine deaminase was purified 3038-fold to apparent homogeneity from human leukaemic granulocytes by adenosine affinity chromatography. The purified enzyme has a specific activity of 486 mumol/min per mg of protein at 35 degrees C. It exhibits a single band when subjected to sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, non-denaturing polyacrylamide-gel electrophoresis and isoelectric focusing. The pI is 4.4. The enzyme is a monomeric protein of molecular weight 44000. Both electrophoretic behaviour and molecular weight differ from those of the low-molecular-weight adenosine deaminase purified from human erythrocytes. Its amino acid composition is reported. Tests with periodic acid-Schiff reagent for associated carbohydrate are negative. Of the large group of physiological compounds tested as potential effectors, none has a significant effect. The enzyme is specific for adenosine and deoxyadenosine, with Km values of 48 microM and 34 microM respectively. There are no significant differences in enzyme function on the two substrates. erythro-9-(2-Hydroxy non-3-yl) adenine is a competitive inhibitor, with Ki 15 nM. Deoxycoformycin inhibits deamination of both adenosine and deoxyadenosine, with an apparent Ki of 60-90 pM. A specific antibody was developed against the purified enzyme, and a sensitive radioimmunoassay for adenosine deaminase protein is described.


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.


1978 ◽  
Vol 173 (3) ◽  
pp. 885-894 ◽  
Author(s):  
R I Bashey ◽  
H M Bashey ◽  
S A Jimenez

Collagens extracted from heart valves by using limited pepsin digestion were fractionated by differential salt precipitation. Collagen types were identified by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, amino acid analysis and cleavage with CNBr. Heart-valve collagen was heterogeneous in nature, consisting of a mixture of type-I and type-III collagens. The identity of type-III collagen was established on the basis of (a) insolubility in 1.7 M-NaC1 at neutral pH, (b) behaviour of this collagen fraction on gel electrophoresis under reducing and non-reducing conditions, (c) amino acid analysis showing a hydroxyproline/proline ratio greater than 1, and (d) profile of CNBr peptides on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis showing a peak characteristic for type-III collagen containing peptides alpha1(III)CB8 and alpha1(III)CB3. In addition to types-I and -III collagen, a collagen polypeptide not previously described in heart valves was identified. This polypeptide represented approx. 30% of the collagen fraction precipitated at 4.0 M-NaCl, it migrated between beta- and alpha1-collagen chains on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and its electrophoretic behaviour was not affected by disulphide-bond reduction. All collagen fractions from the heart valves contained increased amounts of hydroxylysine when compared with type-I and -III collagens from other tissues. The presence of beta- and gamma-chains and higher aggregates in pepsin-solubilized collagen indicated that these collagens were highly cross-linked and suggested that some of these cross-links involved the triple-helical regions of the molecule. It is likely that the higher hydroxylysine content of heart-valve collagen is responsible for the high degree of intermolecular cross-linking and may be the result of an adaptive mechanism for the specialized function of these tissues.


1978 ◽  
Vol 169 (1) ◽  
pp. 251-253 ◽  
Author(s):  
P Lehtovaara

The estimate of the molecular weight of leghaemoglobin by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis is about 20% too low. This is due to an anomalously high limiting relative mobility. Leghaemoglobin binds 1.4 g of sodium dodecyl sulphate/g of protein with a concomitant decrease in the helical content from 71-72% to 49-51%.


1977 ◽  
Vol 163 (3) ◽  
pp. 449-453 ◽  
Author(s):  
M B Baird ◽  
H R Massie ◽  
L S Birnbaum

Ultracentrifugation studies of purified mouse hepatic catalase revealed that 5-7% of the total material consists of a form with a higher molecular weight than the bulk of the catalase. The two components were separated by sucrose-gradient centrifugation. Polyacrylamide-gel electrophoresis (in borate buffer) demonstrated that high-molecular-weight catalase is enriched in a more slowly migrating component, and sodium dodecyl sulphate/polyacrylamide gel-electrophoresis demonstrated that the molecular weight of the subunits of the high-molecular-weight material is identical with that of the subunits of the major form. These results suggest that high-molecular-weight catalase consists of subunits that are not markedly distinct from those present in the normal catalase tetramer.


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