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

Akerstrom, B.; Logdberg, L.; Babiker-Mohammed, H.; Lohmander, S. LU 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
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
  • 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
2016-05-24 12:03:16
@misc{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},
  keyword      = {α1-microglobulin ,animals},
  language     = {eng},
  number       = {1-2},
  pages        = {143--148},
  publisher    = {ARRAY(0x920bf00)},
  series       = {European Journal of Biochemistry},
  title        = {Structural relationship between α1-microglobulin from man, guinea-pig, rat and rabbit},
  volume       = {170},
  year         = {1988},
}