Protein Science CSH PROT
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Right arrow Citation Map
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by DAILEY, T. A.
Right arrow Articles by DAILEY, H. A.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by DAILEY, T. A.
Right arrow Articles by DAILEY, H. A.
Social Bookmarking
Add to CiteULike   Add to Connotea   Add to Del.icio.us   Add to Digg   Add to Reddit   Add to Technorati  
What's this?

Protein Science, Vol 5, Issue 1 98-105, Copyright © 1996 by Cold Spring Harbor Laboratory Press

ARTICLE

Human protoporphyrinogen oxidase: Expression, purification, and characterization of the cloned enzyme

T. A. DAILEY and H. A. DAILEY
Department of Microbiology, Department of Biochemistry and Molecular Biology, and the Center for Metalloenzyme Studies, University of Georgia, Athens, Georgia 30602-2605

Protoporphyrinogen oxidase (E.C.1.3.3.4) catalyzes the oxygen-dependent oxidation of protoporphyrinogen IX to protoporphyrin IX. The enzyme from human placenta has been cloned, sequenced, expressed in Escherichia coli, purified to homogeneity, and characterized. Northern blot analysis of eight different human tissues show evidence for only a single transcript in all tissue types and the size of this transcript is approximately 1.8 kb. The human cDNA has been inserted into an expression vector for E. coli and the protein produced at high levels in these cells. The protein is found in both membrane and cytoplasmic fractions. The enzyme was purified to homogeneity in the presence of detergents using a metal chelate affinity column. The purified protein is a homodimer composed of subunits of a molecular weight of 51,000. The enzyme contains one noncovalently bound FAD per dimer, has a monomer extinction coefficient of 48,000 at 270 nm and contains no detectable redox active metals. The apparent K(m) and K(cat) for protoporphyrinogen IX are 1.7 {mu}M and 10.5 min(-1), respectively. The enzyme does not use coproporphyrinogen III as a substrate and is inhibited by micromolar concentrations of the herbicide acifluorfen. Protein database searches reveal significant homology between protoporphyrinogen oxidase and monoamine oxidase.
Add to CiteULike CiteULike   Add to Connotea Connotea   Add to Del.icio.us Del.icio.us   Add to Digg Digg   Add to Reddit Reddit   Add to Technorati Technorati    What's this?




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS
Copyright © 1996 by The Protein Society.