Structural characterization of inter-alpha-inhibitor. Evidence for an extended shape
(1999) In Journal of Biological Chemistry 274(1). p.298-304- Abstract
- Inter-alpha-inhibitor (IalphaI) is a 180-kDa serum protein consisting of three polypeptides. Two of these, the heavy chains 1 and 2 (H1 and H2), are of 75-80 kDa and have similar amino acid sequences. The third polypeptide, bikunin, has a molecular mass of 25 kDa and contains a 7-kDa chondroitin sulfate chain that is covalently linked to the C-terminal amino acid residues of H1 and H2. IalphaI has been shown to be required for the formation of the hyaluronan-containing extracellular matrix of certain cell types. How IalphaI exerts this function is not known, but it appears that upon interaction with cells, the heavy chains are released and become covalently linked to hyaluronan. Our results indicate that IalphaI and its heavy chains are... (More)
- Inter-alpha-inhibitor (IalphaI) is a 180-kDa serum protein consisting of three polypeptides. Two of these, the heavy chains 1 and 2 (H1 and H2), are of 75-80 kDa and have similar amino acid sequences. The third polypeptide, bikunin, has a molecular mass of 25 kDa and contains a 7-kDa chondroitin sulfate chain that is covalently linked to the C-terminal amino acid residues of H1 and H2. IalphaI has been shown to be required for the formation of the hyaluronan-containing extracellular matrix of certain cell types. How IalphaI exerts this function is not known, but it appears that upon interaction with cells, the heavy chains are released and become covalently linked to hyaluronan. Our results indicate that IalphaI and its heavy chains are extended molecules; thus, upon electron microscopy, IalphaI appeared to consist of two globular domains connected by a thin structure 31-nm long and the isolated heavy chains of a globular domain and a "tail" about 15-nm long. Analysis of the heavy chains by partial proteolysis showed that the C-terminal halves are particularly sensitive to hydrolysis indicating that they are loosely folded. Furthermore, electron microscopy showed that partially degraded heavy chains lacked the extended regions. Taken together, these results suggest that the N-terminal half of the heavy chains forms a globular domain, whereas the other half has an extended and loosely folded structure. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1115491
- author
- Blom, A M ; Mörgelin, Matthias LU ; Oyen, M ; Jarvet, J and Fries, E
- organization
- publishing date
- 1999
- type
- Contribution to journal
- publication status
- published
- subject
- in
- Journal of Biological Chemistry
- volume
- 274
- issue
- 1
- pages
- 298 - 304
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:9867844
- ISSN
- 1083-351X
- language
- English
- LU publication?
- yes
- id
- 188c1ceb-58d8-4330-883b-372e5bcf07d1 (old id 1115491)
- alternative location
- http://www.jbc.org/cgi/content/full/274/1/298
- date added to LUP
- 2016-04-01 11:51:28
- date last changed
- 2018-11-21 20:01:02
@article{188c1ceb-58d8-4330-883b-372e5bcf07d1, abstract = {{Inter-alpha-inhibitor (IalphaI) is a 180-kDa serum protein consisting of three polypeptides. Two of these, the heavy chains 1 and 2 (H1 and H2), are of 75-80 kDa and have similar amino acid sequences. The third polypeptide, bikunin, has a molecular mass of 25 kDa and contains a 7-kDa chondroitin sulfate chain that is covalently linked to the C-terminal amino acid residues of H1 and H2. IalphaI has been shown to be required for the formation of the hyaluronan-containing extracellular matrix of certain cell types. How IalphaI exerts this function is not known, but it appears that upon interaction with cells, the heavy chains are released and become covalently linked to hyaluronan. Our results indicate that IalphaI and its heavy chains are extended molecules; thus, upon electron microscopy, IalphaI appeared to consist of two globular domains connected by a thin structure 31-nm long and the isolated heavy chains of a globular domain and a "tail" about 15-nm long. Analysis of the heavy chains by partial proteolysis showed that the C-terminal halves are particularly sensitive to hydrolysis indicating that they are loosely folded. Furthermore, electron microscopy showed that partially degraded heavy chains lacked the extended regions. Taken together, these results suggest that the N-terminal half of the heavy chains forms a globular domain, whereas the other half has an extended and loosely folded structure.}}, author = {{Blom, A M and Mörgelin, Matthias and Oyen, M and Jarvet, J and Fries, E}}, issn = {{1083-351X}}, language = {{eng}}, number = {{1}}, pages = {{298--304}}, publisher = {{American Society for Biochemistry and Molecular Biology}}, series = {{Journal of Biological Chemistry}}, title = {{Structural characterization of inter-alpha-inhibitor. Evidence for an extended shape}}, url = {{http://www.jbc.org/cgi/content/full/274/1/298}}, volume = {{274}}, year = {{1999}}, }