Expression of a functional proteinase inhibitor capable of accepting xylose: bikunin
Author
Summary, in English
Bikunin is a Kunitz-type proteinase inhibitor, which is cross-linked to heavy chains via a chondroitin sulfate chain, forming inter-alpha-inhibitor and related molecules. Rat bikunin was produced by baculovirus-infected insect cells. The protein could be purified with a total yield of 20 mg/liter medium. Unlike naturally occuring bikunin the recombinant protein had no galactosaminoglycan chain. Endoglycosidase digestion also suggested that the recombinant form lacked N-linked oligosaccharides. Bikunin is translated as a part of a precursor, alpha1-microglobulin/bikunin, but the functional significance of the cotranslation is unknown. Our results indicate that the proteinase inhibitory function of bikunin is not regulated by the alpha1-microglobulin-part of the alpha1-microglobulin/bikunin precursor since recombinant bikunin had the same trypsin inhibitory activity as the recombinant precursor. Both free bikunin and the precursor were also functional as a substrate in an in vitro xylosylation system. This demonstrates that the alpha1-microglobulin-part is not necessary for the first step of galactosaminoglycan assembly.
Department/s
- Department of Experimental Medical Science
- Immunology
- Breastcancer-genetics
- Matrix Biology
- Infection Medicine (BMC)
Publishing year
2001
Language
English
Pages
99-106
Publication/Series
Archives of Biochemistry and Biophysics
Volume
387
Issue
1
Document type
Journal article
Publisher
Academic Press
Topic
- Infectious Medicine
- Cancer and Oncology
- Cell and Molecular Biology
- Immunology in the medical area
Keywords
- bikunin
- greek small letter alpha1-microglobulin/bikunin precursor
- proteinase inhibition
- xylosylation
- insect cells
Status
Published
Research group
- Immunology
- Matrix Biology
ISBN/ISSN/Other
- ISSN: 0003-9861