Biochemical and immunological characterization of three binding sites on human plasma fibronectin with different affinities for heparin

Biochemistry ◽  
1983 ◽  
Vol 22 (17) ◽  
pp. 4113-4119 ◽  
Author(s):  
Leslie I. Gold ◽  
Blas Frangione ◽  
Edward Pearlstein
1977 ◽  
Vol 163 (3) ◽  
pp. 419-426 ◽  
Author(s):  
E A Neuwelt ◽  
M Schmukler ◽  
M S Niziak ◽  
P B Jewett ◽  
C C Levy

RNAases (ribonucleases), purified from four human tissues, as well as bovine pancreatic RNAase (RNAase A), were studied by immunodiffusion methods and by two different primary binding tests. The enzymes fell into two groups immunologically, those purified from plasma and pancreas in one and those from spleen and liver in the other. No antigenic cross-reaction between the two groups was detected by any of the immunoassays used. There was a slight antigenic cross-reaction between the human and bovine pancreatic RNAases. The liver and spleen RNAases were immunologically identical by all criteria used, whereas a small but consistent antigenic difference between the human plasma and human pancreas enzymes was detected. The significance of this difference between the human plasma and pancreas RNAases is discussed in relation to similarities and differences in their properties.


1980 ◽  
Vol 191 (3) ◽  
pp. 719-727 ◽  
Author(s):  
M Vuento ◽  
E Salonen ◽  
K Salminen ◽  
M Pasanen ◽  
U K Stenman

Human plasma fibronectin has been purified by a non-denaturing affinity chromatography procedure [Vuento & Vaheri, (1979) Biochem.J. 183, 331–337], and antisera have been raised by immunizing rabbits with the native protein. The antisera reacted strongly with native fibronectin, but only weakly with reduced and alkylated fibronectin or with heat-denaturated fibronectin. Denaturation also affected the haemagglutinating and gelatin-binding activities of fibronectin and increased its susceptibility to proteolytic degradation. The antisera reacted with fragments of fibronectin obtained by proteolysis with plasmin. Large fragments (mol.wt. 180000–200000), lacking the region harbouring the interchain disulphide bridges but containing the sites responsible for gelatin-binding and haemagglutinating activity, showed as intense a reaction with the antisera as intact fibronectin. Smaller peptides showed a weaker reaction. All fragments tested showed sensitivity to denaturation in their reaction with the antisera. The results were interpreted as showing that: (1) native fibronectin has an ordered conformation that is easily perturbed by denaturation; (2) most of the antigenic determinants of the protein are dependent on conformation; (3) the region of the fibronectin molecule containing the interchain disulphide bridges has only few antigenic determinants; and (4) covalent interaction of the two subunits does not contribute to the antigenic structure recognized by rabbit antisera. The observed correlation between the antigenic activity and a structural and functional intactness of fibronectin suggests that the antibodies to native fibronectin could be used as a conformational probe in studies on this protein.


Author(s):  
Yu Yamaguchi ◽  
Mamoru Isemura ◽  
Masashi Kosakai ◽  
Akira Sato ◽  
Masakuni Suzuki ◽  
...  

1987 ◽  
Vol 241 (3) ◽  
pp. 923-928 ◽  
Author(s):  
A Garcia-Pardo ◽  
A Rostagno ◽  
B Frangione

The primary structure of a 38 kDa heparin-binding domain from human plasma fibronectin has been determined. This domain contains 380 residues arranged in three type-III homology regions of approx. 90 residues each, and a 67-amino-acid C-terminal segment. This segment has been shown to be encoded by certain mRNA species only, due to alternative splicing [Kornblihtt, Vibe-Pedersen & Baralle (1984) Nucleic Acids Research 12, 5853-5868], and therefore represents a region of heterogeneity in fibronectin. Our data indicate that at least one of the constituent polypeptide chains contains this region.


1975 ◽  
Vol 151 (3) ◽  
pp. 469-475 ◽  
Author(s):  
N Phillips ◽  
D Robinson ◽  
B Winchester

Antiserum was raised against purified human liver α-D-mannosidase B. It precipitated α-mannosidases A and B from solution, demonstrating the close structural resemblance of these 2 forms of acidic α-mannosidase activity. A continuous enzymically active precipitin line with no spurs was obtained when α-mannosidase A and B were placed in adjacent wells on Ouchterlony double-diffusion plates. The antiserum precipitated acidic but not neutral α-mannosidase from an extract of human liver, confirming that the acidic and neutral activities are not closely related. Acidic activity was also precipitated from extracts of human brain, kidney and leucocytes by the antiserum. However, it did not cross-react with bovine acidic α-mannosidase activity or with the activity in human plasma that has an optimum pH of 5.5. The two acidic forms of human liver α-mannosidase, A and B, are immunologically identical but distinct from neutral α-mannosidase and that activity with an optimum pH of 5.5.


1983 ◽  
Vol 215 (3) ◽  
pp. 613-616 ◽  
Author(s):  
M Vuento ◽  
K Sekiguchi ◽  
M Korkolainen

Limited proteolysis of human plasma fibronectin with chymotrypsin, trypsin or thermolysin has been used to localize binding sites responsible for binding [Vuento, Korkolainen & Stenman (1982) Biochem. J. 205, 303-311] of fibronectin to carboxy-group-modified proteins. These bindings sites are different from those mediating binding of fibronectin to gelatin or heparin. They are located close to the C-terminus of the polypeptide chains of fibronectin, and apparently overlap with the C-terminal fibrin binding site.


1981 ◽  
Author(s):  
A Takada ◽  
K Mochizuki ◽  
Y Takada

Streptokinase (SK) forms a complex with human plasminogen (plg) or plasmin, and the resulting complex (SK-activator) functions to convert plg to plasmin. We have indicated that human plasma contains a factor (SK-potentiator) which potentiates the capacity of SK to activate human plg. SK-potentiator has a molecular weight of 240,000, and composed of β and γ-chains of fibrinogen, α-chain being degraded. SK-potentiator crossreacts with anti-FDP-Y fragment. Immunodiffusion shows that SK-potentiator has an antigenic determinant in common with both FDP-Y and fibrinogen, and the other determinant not in common with fibrinogen but FDP-Y. Early FgDP potentiates SK-activator activity as much as SK-potentiator, but further degraded FgDP potentiates less than fibrinogen which still enhances SK-activator activity. The addition of thrombin to FgDP or SK-potentiator enhances SK-activator activity more than SK-potentiator. Thus removal of fibrinopeptides from FgDP or SK-potentiator results in better potentiator activity. When tranexamic acid (l mM) was added to the mixture of Glu-plg and UK, the activation of Glu-plg was enhanced, but tranexamic acid (l mM) added to SK-activator caused a decrease in SK-activator activity. The addition of fibrinogen or SK-potentiator to the mixture of tranexamic acid and SK-activator prevented the decrease of SK-activator activity to some extent, which may indicate that SK-potentiator competes with tranexamic acid for lysine binding sites (LBS) of plg and SK-potentiator forms a complex with SK-activator in spite of the presence of tranexamic acid. It is proposed that SK-potentiator binds with LBS of plg part of SK-activator and SK combines with light chain part of plg, the resulting SK-plg-potentiator complex being the better activator than SK-plg or SK-plasmin complex.


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