22 December 2006
Investigation of the catalytic and structural roles of conserved histidines of human coproporphyrinogen oxidase using site-directed mutagenesisShani J. Gitter, Christopher L. Cooper, Jon A. Friesen, Timothy D. Lash, Marjorie A. Jones
Med Sci Monit 2007; 13(1): BR1-10 :: ID: 470138
Background: The catalytic contribution of four conserved histidines of human coproporphyrinogen oxidase (CPO) has been investigated using site-directed mutagenesis to change histidine (H) into alanine (A).
Material/Methods: The wild-type and mutant enzyme forms were analyzed for their ability to utilize coproporphyrinogen- III, mesoporphyrinogen-VI, and harderoporphyrinogen as substrates.
Results: Wild-type CPO had specifi c activities of 4.9±0.9 nmole product/min/mg for coproporphyrinogen- III, 1.7±0.7 nmole product/min/mg for mesoporphyrinogen-VI, and 5.1±1.8 nmole product/ min/mg for harderoporphyrinogen. The four mutant enzymes were catalytically competent
with all three substrates, but to varying degrees. The most affected mutant was the H158A enzyme which exhibited approximately 50-fold lower activity than wild-type recombinant CPO.
Conclusions: Thus, His158 of human CPO may have a role in the active site, but none of the conserved histidine residues of human coproporphyrinogen oxidase is essential for catalytic activity although changes in histidines have been implicated in the disease state hereditary coproporphyria.
Keywords: Conserved Sequence, Catalysis, Amino Acid Sequence, Coproporphyrinogen Oxidase - metabolism, Coproporphyrinogens - chemistry, Escherichia coli, Gene Expression, Histidine - metabolism, Kinetics, Molecular Sequence Data, Mutagenesis, Site-Directed, Mutant Proteins - metabolism, Oligopeptides, Recombinant Proteins - metabolism, Structure-Activity Relationship
04 June 2022 : EditorialEditorial: Acute Hepatitis of Unknown Origin in Children. Is Autoimmunity at Play?
Med Sci Monit 2022; 28:e937371
27 June 2022 : Clinical ResearchShoulder Injury Related to Vaccine Administration (SIRVA) in 16 Patients Following COVID-19 Vaccination Who...
Med Sci Monit In Press; DOI: 10.12659/MSM.937430
04 June 2022 : Clinical ResearchScreening for SARS-CoV-2 Infection in Students at the Medical University of Warsaw, Poland Between November...
Med Sci Monit 2022; 28:e936962
30 May 2022 : Clinical ResearchEffects of Wearing Face Masks on Exercise Capacity and Ventilatory Anaerobic Threshold in Healthy Subjects ...
Med Sci Monit 2022; 28:e936069
30 Jun 2022 : Clinical ResearchAntioxidant System and Ions Concentrations After Femoral Neck and Resurfacing Hip Arthroplasty
Med Sci Monit In Press; DOI: 10.12659/MSM.936335
28 Jun 2022 : Meta-AnalysisUrodynamics in Early Diagnosis of Diabetic Bladder Dysfunction in Women: A Systematic Review and Meta-Analysis
Med Sci Monit In Press; DOI: 10.12659/MSM.937166
28 Jun 2022 : Clinical ResearchSerum Calprotectin – a NET Product – as a Biomarker of Disease Activity in Patients with Systemic Lupus Ery...
Med Sci Monit In Press; DOI: 10.12659/MSM.936534
Most Viewed Current Articles
30 Dec 2021 : Clinical ResearchRetrospective Study of Outcomes and Hospitalization Rates of Patients in Italy with a Confirmed Diagnosis o...
Med Sci Monit 2021; 27:e935379
08 Mar 2022 : Review articleA Review of the Potential Roles of Antioxidant and Anti-Inflammatory Pharmacological Approaches for the Man...
Med Sci Monit 2022; 28:e936292
01 Nov 2020 : Review articleLong-Term Respiratory and Neurological Sequelae of COVID-19
Med Sci Monit 2020; 26:e928996