Prothrombin, albumin and immunoglobulin A form covalent complexes with alpha1-microglobulin in human plasma
(1997) In European Journal of Biochemistry 245(3). p.83-676- Abstract
Molecules containing the 33-kDa plasma protein alpha1-microglobulin were isolated from human plasma by anti-(alpha1-microglobulin) affinity chromatography. Five major bands could be seen after electrophoretic separation of the alpha1-microglobulin-containing proteins under native conditions. Immunoblotting demonstrated alpha1-microglobulin in all five bands. Two of these have been described previously: free alpha1-microglobulin and alpha1-microglobulin complexed with IgA (IgA x alpha1-microglobulin). The other three bands were identified as prothrombin alpha1-microglobulin, albumin x alpha1-microglobulin and dimeric alpha1-microglobulin. Prothrombin x alpha1-microglobulin were 1:2 and 1:1 complexes which carried approximately 1% of... (More)
Molecules containing the 33-kDa plasma protein alpha1-microglobulin were isolated from human plasma by anti-(alpha1-microglobulin) affinity chromatography. Five major bands could be seen after electrophoretic separation of the alpha1-microglobulin-containing proteins under native conditions. Immunoblotting demonstrated alpha1-microglobulin in all five bands. Two of these have been described previously: free alpha1-microglobulin and alpha1-microglobulin complexed with IgA (IgA x alpha1-microglobulin). The other three bands were identified as prothrombin alpha1-microglobulin, albumin x alpha1-microglobulin and dimeric alpha1-microglobulin. Prothrombin x alpha1-microglobulin were 1:2 and 1:1 complexes which carried approximately 1% of total alpha1-microglobulin, had molecular masses of about 145 kDa and 110 kDa upon SDS/PAGE and dissociated completely to free alpha1-microglobulin and prothrombin (72 kDa) when reducing agents were added, suggesting that the complexes were stabilized by disulfide bonds. The alpha1-microglobulin molecules did not inhibit cleavage of prothrombin by factor Xa and were bound to the peptides which were released upon activation of prothrombin. Albumin x alpha1-microglobulin, corresponding to 7% of total plasma alpha1-microglobulin, was a mixture between 1:1 and 1:2 complexes, with masses upon SDS/PAGE of approximately 100 kDa and 135 kDa, respectively. Both these complexes dissociated only partially to free alpha1-microglobulin and albumin when reducing agents were added. The albumin x alpha1-microglobulin complexes carried a yellow-brown chromophore similar to free alpha1-microglobulin. The complex-binding to alpha1-microglobulin did not block the fatty-acid-binding ability of albumin. The plasma concentrations of albumin x alpha1-microglobulin and prothrombin x alpha1-microglobulin were estimated to 5.2 mg/l and 1.1 mg/l, respectively.
(Less)
- author
- Berggård, T LU ; Thelin, N ; Falkenberg, C LU ; Enghild, J J and Akerström, B LU
- organization
- publishing date
- 1997-05-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Alpha-Globulins/chemistry, Humans, Immunoglobulin A/blood, Macromolecular Substances, Protein Binding, Prothrombin/chemistry, Serum Albumin/chemistry
- in
- European Journal of Biochemistry
- volume
- 245
- issue
- 3
- pages
- 83 - 676
- publisher
- Wiley-Blackwell
- external identifiers
-
- pmid:9183005
- scopus:0030950688
- ISSN
- 0014-2956
- DOI
- 10.1111/j.1432-1033.1997.00676.x
- language
- English
- LU publication?
- yes
- id
- 1902a267-d696-4ac2-98bd-ac48db59298f
- date added to LUP
- 2019-05-22 10:17:32
- date last changed
- 2024-05-14 10:35:33
@article{1902a267-d696-4ac2-98bd-ac48db59298f,
abstract = {{<p>Molecules containing the 33-kDa plasma protein alpha1-microglobulin were isolated from human plasma by anti-(alpha1-microglobulin) affinity chromatography. Five major bands could be seen after electrophoretic separation of the alpha1-microglobulin-containing proteins under native conditions. Immunoblotting demonstrated alpha1-microglobulin in all five bands. Two of these have been described previously: free alpha1-microglobulin and alpha1-microglobulin complexed with IgA (IgA x alpha1-microglobulin). The other three bands were identified as prothrombin alpha1-microglobulin, albumin x alpha1-microglobulin and dimeric alpha1-microglobulin. Prothrombin x alpha1-microglobulin were 1:2 and 1:1 complexes which carried approximately 1% of total alpha1-microglobulin, had molecular masses of about 145 kDa and 110 kDa upon SDS/PAGE and dissociated completely to free alpha1-microglobulin and prothrombin (72 kDa) when reducing agents were added, suggesting that the complexes were stabilized by disulfide bonds. The alpha1-microglobulin molecules did not inhibit cleavage of prothrombin by factor Xa and were bound to the peptides which were released upon activation of prothrombin. Albumin x alpha1-microglobulin, corresponding to 7% of total plasma alpha1-microglobulin, was a mixture between 1:1 and 1:2 complexes, with masses upon SDS/PAGE of approximately 100 kDa and 135 kDa, respectively. Both these complexes dissociated only partially to free alpha1-microglobulin and albumin when reducing agents were added. The albumin x alpha1-microglobulin complexes carried a yellow-brown chromophore similar to free alpha1-microglobulin. The complex-binding to alpha1-microglobulin did not block the fatty-acid-binding ability of albumin. The plasma concentrations of albumin x alpha1-microglobulin and prothrombin x alpha1-microglobulin were estimated to 5.2 mg/l and 1.1 mg/l, respectively.</p>}},
author = {{Berggård, T and Thelin, N and Falkenberg, C and Enghild, J J and Akerström, B}},
issn = {{0014-2956}},
keywords = {{Alpha-Globulins/chemistry; Humans; Immunoglobulin A/blood; Macromolecular Substances; Protein Binding; Prothrombin/chemistry; Serum Albumin/chemistry}},
language = {{eng}},
month = {{05}},
number = {{3}},
pages = {{83--676}},
publisher = {{Wiley-Blackwell}},
series = {{European Journal of Biochemistry}},
title = {{Prothrombin, albumin and immunoglobulin A form covalent complexes with alpha1-microglobulin in human plasma}},
url = {{http://dx.doi.org/10.1111/j.1432-1033.1997.00676.x}},
doi = {{10.1111/j.1432-1033.1997.00676.x}},
volume = {{245}},
year = {{1997}},
}