RGD Reference Report - Rat harderian gland porphobilinogen deaminase: characterization studies and regulatory action of protoporphyrin IX. - Rat Genome Database

Send us a Message
Submit Data |  Help |  Video Tutorials |  News |  Publications |  Download |  REST API |  Citing RGD |  Contact   
Search RGD Grant Resources Citing RGD About Us Contact Us
Genes Variants Community Projects QTLs Strains Markers Genome Information Ontologies Cell Lines References Download Submit Data
OntoMate (Literature Search) JBrowse (Genome Browser) Synteny Browser (VCMap) Variant Visualizer Multi-Ontology Enrichment (MOET) Gene-Ortholog Location Finder (GOLF) InterViewer (Protein-Protein Interactions) PhenoMiner (Quatitative Phenotypes) Gene Annotator OLGA (Gene List Generator) AllianceMine GViewer (Genome Viewer)
Aging & Age-Related Disease Cancer & Neoplastic Disease Cardiovascular Disease Coronavirus Disease Developmental Disease Diabetes Hematologic Disease Immune & Inflammatory Disease Infectious Disease Liver Disease Neurological Disease Obesity & Metabolic Syndrome Renal Disease Respiratory Disease Sensory Organ Disease
Find Models Genetic Models Autism Models Rat PhenoMiner (Quantitative Phenotypes) Chinchilla PhenoMiner Expected Ranges (Quantitative Phenotype) PhenoMiner Term Comparison Hybrid Rat Diversity Panel Phenotypes Phenotypes in Other Animal Models Animal Husbandry Strain Medical Records Phylogenetics Strain Availability Calendar Rats 101 Submissions Photo Archive
Pathways
Rat Community Forum Directory of Rat Laboratories Video Tutorials News RGD Publications RGD Presentations Archive Nomenclature Guidelines Resource Links Laboratory Resources Employment Resources
Advanced Search (OLGA)

Rat harderian gland porphobilinogen deaminase: characterization studies and regulatory action of protoporphyrin IX.

Authors: Cardalda, CA  Juknat, AA  Princ, FG  Batlle, A 
Citation: Cardalda CA, etal., Arch Biochem Biophys. 1997 Nov 1;347(1):69-77.
RGD ID: 2301695
Pubmed: PMID:9344466   (View Abstract at PubMed)
DOI: DOI:10.1006/abbi.1997.0310   (Journal Full-text)

Properties of purified porphobilinogen deaminase (PBG-D; EC 4.3.1.8) from rat harderian gland are here presented. The enzyme behaves as a monomer of Mr 38 +/- 2 kDa and is optimally active at pH 8.0-8.2. Its activation energy, determined by an Arrhenius plot, is 76.1 kJ/mol. Initial velocity studies showed a linear progress curve for uroporphyringen I formation and a hyperbolic dependence of the initial rate on substrate concentration, indicating the existence of a sequential displacement mechanism. Apparent kinetic constants, Km and Vm, calculated at 37 degrees C and pH 8.0 were 1.1 microM and 170 pmol/min mg, respectively. The pH dependence of the apparent kinetic parameters revealed the ionization of residues with pKAES and pKBES of 7.4 +/- 0.1 and 8.6 +/- 0.1, respectively, and a pKE value of 8.0 +/- 0.1. Incubation of PBG-D with 5.0 mM N-ethylmaleimide and 5.0 mM 5,5'-dithiobis(2-nitrobenzoic acid) at pH 8.0 led to inhibitions of 70 and 50%, respectively. The effect of pH, as well as the effect of thiol reagents, on enzyme activity strongly suggests the involvement of cysteine residue(s) in the mechanism of uroporphyrinogen I biosynthesis, in both the catalytic reaction and the substrate binding. Rat harderian gland PBG-D activity decreased with increasing concentrations of protoporphyrin IX, reaching a 40% inhibition at the in vivo concentration of the porphyrin and 7 microM PBG. Even at saturating concentrations of substrate, inhibition by protoporphyrin was not completely reversed. So, accumulated porphyrin may act as an regulator of PBG-D activity in rat harderian gland.



Gene Ontology Annotations    Click to see Annotation Detail View

Biological Process

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
HmbsRattetrapyrrole biosynthetic process  IDA  RGD 

Molecular Function

  
Object SymbolSpeciesTermQualifierEvidenceWithNotesSourceOriginal Reference(s)
HmbsRatamine binding  IPIporphobilinogensubstrate porphobilinogen bindingRGD 
HmbsRatcarboxylic acid binding  IPIporphobilinogensubstrate porphobilinogen bindingRGD 
HmbsRathydroxymethylbilane synthase activity  IDA  RGD 

Objects Annotated

Genes (Rattus norvegicus)
Hmbs  (hydroxymethylbilane synthase)


Additional Information