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Structural relationship between α1-microglobulin from man, guinea-pig, rat and rabbit

Akerstrom, B. LU ; Logdberg, L. ; Babiker-Mohammed, H. ; Lohmander, S. LU orcid and Rask, L. (1988) In European Journal of Biochemistry 170(1-2). p.143-148
Abstract

Rabbit α1-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α1-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α1-microglobulin has previously been purified from the urine of humans, guinea-pigs and rats by similar methods, and the molecular masses of the four homologues were compared by SDS/polyacrylamide gel electrophoresis and gel chromatography in a denaturing medium. By these two methods the human homologue was 6 kDa and 3 kDa larger, respectively, than the other three... (More)

Rabbit α1-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α1-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α1-microglobulin has previously been purified from the urine of humans, guinea-pigs and rats by similar methods, and the molecular masses of the four homologues were compared by SDS/polyacrylamide gel electrophoresis and gel chromatography in a denaturing medium. By these two methods the human homologue was 6 kDa and 3 kDa larger, respectively, than the other three proteins. Endoglycosidase F digestion of α1-microglobulin, followed by SDS/polyacrylamide gel electrophoresis, revealed three protein bands in the human α1-microglobulin sample, and only two bands in guinea-pig, rat and rabbit α1-microglobulin, with a gap between each band of 2.6-2.9 kDa. The amino-terminal amino acid sequences of the four homologues were determined and between 72% and 81% homology was seen. The five amino-terminal amino acids present in the other species were missing in guinea-pig α1-microglobulin. Our results indicate that human α1-microglobulin is substituted with two N-linked oligosaccharides, while only one is attached to each of the other α1-microglobulins, and that the extra glycosylamine-linked oligosaccharide in the human protein is attached to asparagine in position 17. Finally it is shown that all four homologues inhibit antigen stimulation of human lymphocytes, a finding which is consistent with our previous suggestion that the N-linked oligosaccharides carry the immunosuppressive activity of α1-microglobulin.

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author
; ; ; and
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
α1-microglobulin, animals
in
European Journal of Biochemistry
volume
170
issue
1-2
pages
6 pages
publisher
Wiley-Blackwell
external identifiers
  • pmid:2446872
  • scopus:0023870569
ISSN
0014-2956
language
English
LU publication?
yes
id
04be53b7-43d8-4808-94c2-112cfd964831
date added to LUP
2016-05-04 12:59:34
date last changed
2024-01-04 02:43:03
@article{04be53b7-43d8-4808-94c2-112cfd964831,
  abstract     = {{<p>Rabbit α<sub>1</sub>-microglobulin was purified from the urine of sodium-chromate-treated animals by the use of gel chromatography on Sephadex G-100 affinity chromatography on concanavalin-A - Sepharose and ion-exchange chromatography on DEAE-Sephadex. Rabbit α<sub>1</sub>-microglobulin had a molecular mass of 25.6 kDa on SDS/polyacrylamide gel electrophoresis. α<sub>1</sub>-microglobulin has previously been purified from the urine of humans, guinea-pigs and rats by similar methods, and the molecular masses of the four homologues were compared by SDS/polyacrylamide gel electrophoresis and gel chromatography in a denaturing medium. By these two methods the human homologue was 6 kDa and 3 kDa larger, respectively, than the other three proteins. Endoglycosidase F digestion of α<sub>1</sub>-microglobulin, followed by SDS/polyacrylamide gel electrophoresis, revealed three protein bands in the human α<sub>1</sub>-microglobulin sample, and only two bands in guinea-pig, rat and rabbit α<sub>1</sub>-microglobulin, with a gap between each band of 2.6-2.9 kDa. The amino-terminal amino acid sequences of the four homologues were determined and between 72% and 81% homology was seen. The five amino-terminal amino acids present in the other species were missing in guinea-pig α<sub>1</sub>-microglobulin. Our results indicate that human α<sub>1</sub>-microglobulin is substituted with two N-linked oligosaccharides, while only one is attached to each of the other α<sub>1</sub>-microglobulins, and that the extra glycosylamine-linked oligosaccharide in the human protein is attached to asparagine in position 17. Finally it is shown that all four homologues inhibit antigen stimulation of human lymphocytes, a finding which is consistent with our previous suggestion that the N-linked oligosaccharides carry the immunosuppressive activity of α<sub>1</sub>-microglobulin.</p>}},
  author       = {{Akerstrom, B. and Logdberg, L. and Babiker-Mohammed, H. and Lohmander, S. and Rask, L.}},
  issn         = {{0014-2956}},
  keywords     = {{α1-microglobulin; animals}},
  language     = {{eng}},
  number       = {{1-2}},
  pages        = {{143--148}},
  publisher    = {{Wiley-Blackwell}},
  series       = {{European Journal of Biochemistry}},
  title        = {{Structural relationship between α1-microglobulin from man, guinea-pig, rat and rabbit}},
  volume       = {{170}},
  year         = {{1988}},
}