Year-end Sale % OFF 
Abstract
Chicken liver xanthine dehydrogenase, like other xanthine-oxidizing enzymes, is a dimer of Mr = 150,000 subunits. Each subunit contains one molybdenum, one FAD, and two distinct Fe2S2 centers. Treatment with a number of proteases shows that the native enzyme subunit is cleaved at three distinct sites. However, the cleavage products can be separated only under denaturing conditions. Prolonged treatment with subtilisin at pH 10.1 has permitted the isolation of an Mr = 65,000 catalytically active fragment that is devoid of FAD but which contains the molybdenum and both types of iron-sulfur center. A model of the domain structure of the native enzyme is proposed.
Highlights
Chicken liver xanthine dehydrogenase, like other xanthine-oxidizing enzymes, is a dimer of M,. = 150,000 subunits
We describe the effects of various proteolytic enzymes on the structure and function of chicken liver xanthine dehydrogenase and report the isolation of a catalytically active minimal fragment (MY = 65,000) containing the molybdenum, (Fe2S2)I, and (Fe&)11 centers
Our results clearly show that chicken liver xanthine dehydrogenase does not undergo conversion to oxidase on treatment with trypsin
Summary
I, and (Received for publication, April 13, 1979, and in revised form, July 19, 1979). Each subunit contains one molybdenum, one FAD, and two distinct Fe& centers. Treatment with a number of proteases shows that the native enzyme subunit is cleaved at three distinct sites. = 65,000 catalytically active fragment that is devoid of FAD but which contains the molybdenum and both types of ironsulfur center. Xanthine oxidase (EC 1.2.3.2) and the related xanthine dehydrogenase (EC 1.2.1.37) are comprised of two apparently identical subunits, each of which contains 1 atom of molybdenum, 1 molecule of flavin, and 2 separate Fez& clusters We describe the effects of various proteolytic enzymes on the structure and function of chicken liver xanthine dehydrogenase and report the isolation of a catalytically active minimal fragment (MY = 65,000) containing the molybdenum, (Fe2S2)I, and (Fe&) centers
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
