Archibald, Trefan

Bollivar, Faculty Advisor, David

Dulac, Jason

Digital Commons @ Illinois Wesleyan University

Illinois Wesleyan UniversityDigital Commons @ IWUJohn Wesley Powell Student ResearchConference 2005, 16th Annual JWP ConferenceApr 16th, 9:00 AM - 10:00 AMHeterologous Expression, Purification, andCharacterization of Porphobilinogen Synthasefrom Rhodobacter SphaeroidesJason DulacIllinois Wesleyan UniversityTrefan ArchibaldIllinois Wesleyan UniversityDavid Bollivar, Faculty AdvisorIllinois Wesleyan UniversityFollow this and additional works at: http://digitalcommons.iwu.edu/jwprcThis Event is brought to you for free and open access by The Ames Library, the Andrew W. Mellon Center for Curricular and FacultyDevelopment, the Office of the Provost and the Office of the President. It has been accepted for inclusion in Digital Commons @ IWU bythe faculty at Illinois Wesleyan University. For more information, please contact digitalcommons@iwu.edu.©Copyright is owned by the author of this document.Jason Dulac; Trefan Archibald; and David Bollivar, Faculty Advisor, "Heterologous Expression, Purification, andCharacterization of Porphobilinogen Synthase from Rhodobacter Sphaeroides" (April 16, 2005). John Wesley PowellStudent Research Conference. Paper 33.http://digitalcommons.iwu.edu/jwprc/2005/posters/33p HETEROLOGOUS EXPRESSION, PURIFICATION, AND CHARACTERIZATION OF PORPHOBILINOGEN SYNTHASE FROM RHODOBACTER SPHAEROIDES Jason Dulac, Trefan Archibald and David Bollivar* Department of Biology, Illinois Wesleyan University The enzyme porphobilinogen synthase (PBGS, EC 4.2. 1 .24) catalyzes the first common step in the biosynthesis of tetrapyrrole pigments-- such as heme, chlorophyll, and vitamin B 1 2  (cobalamin)-- by converting .two mol�cules of d-aminolevulinic acid (ALA) into porphobilinogen (PBG) 1 .  PBGS IS categonzed by presence or absence of catalytic and allosteric metal ions. All known PBGS sequences contain either a catalytic zinc ion or an allosteric magnesium ion except for those sequences expressed by Rhodobacter capsluatus and Rhodobacter sphaeroids 2. This study presents initial efforts to characterize PBGS in R. sphaeroides in order to better-understand the enzymeis unique characteristics. Evaluating ion dependence fo! R. sphaeroides PBGS is especially important due to an observed dependence upon dIvalent cations in the majority of know PBGS enzymes. Protein assays were carried out to determine the effect of various ions including monovalent cations (Na+, NH4+, K+), d! iyalent cations (Mg2+), and divalent anions (S042-). Additionally, substrate concentratlon was altered for use in Km and Vmax determinations at varying pH values. The observation that specific activity shows protein concentration dependence suggests that PBGS can dissociate into smaller and less active subunits. 

Heterologous Expression, Purification, and Characterization of Porphobilinogen Synthase from Rhodobacter Sphaeroides

http://digitalcommons.iwu.edu/cgi/viewcontent.cgi?article=1825&context=jwprc

Heterologous Expression, Purification, and Characterization of Porphobilinogen Synthase from Rhodobacter Sphaeroides

Abstract

Similar works

Full text

Available Versions

Digital Commons @ Illinois Wesleyan University