ArticleProtein science : a publication of the Protein Society2005
Conversion of 5-aminolevulinate synthase into a more active enzyme by linking the two subunits: spectroscopic and kinetic properties.
Article in Protein science : a publication of the Protein Society, 2005. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 14 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
14 citing papers in PubMed, 26 citations in OpenAlex.
- Article
- Expanded Substrate Specificity in D-Amino Acid Transaminases: A Case Study of Transaminase fromInternational journal of molecular sciences · 2023Article
- The yeast ALA synthase C-terminus positively controls enzyme structure and function.Protein science : a publication of the Protein Society · 2023Article
- Pyridoxal-5'-phosphate as an oxygenase cofactor: Discovery of a carboxamide-forming, α-amino acid monooxygenase-decarboxylase.Proceedings of the National Academy of Sciences of the United States of America · 2018Article
- Human Erythroid 5-Aminolevulinate Synthase Mutations Associated with X-Linked Protoporphyria Disrupt the Conformational Equilibrium and Enhance Product Release.Biochemistry · 2015Article
- Catalytically active alkaline molten globular enzyme: Effect of pH and temperature on the structural integrity of 5-aminolevulinate synthase.Biochimica et biophysica acta · 2014Article
- Molecular enzymology of 5-aminolevulinate synthase, the gatekeeper of heme biosynthesis.Biochimica et biophysica acta · 2011Review
- Functional asymmetry for the active sites of linked 5-aminolevulinate synthase and 8-amino-7-oxononanoate synthase.Archives of biochemistry and biophysics · 2011Article
- Serine 254 enhances an induced fit mechanism in murine 5-aminolevulinate synthase.The Journal of biological chemistry · 2010Article
- Mutation of His465 alters the pH-dependent spectroscopic properties of Escherichia coli glutamate decarboxylase and broadens the range of its activity toward more alkaline pH.The Journal of biological chemistry · 2009Article
- Purification, crystallization and preliminary X-ray analysis of NtdA, a putative pyridoxal phosphate-dependent aminotransferase from Bacillus subtilis.Acta crystallographica. Section F, Structural biology and crystallization communications · 2009Article
- 5-aminolevulinate synthase: catalysis of the first step of heme biosynthesis.Cellular and molecular biology (Noisy-le-Grand, France) · 2009Review
- Histidine 282 in 5-aminolevulinate synthase affects substrate binding and catalysis.Biochemistry · 2007Article
- Escherichia coli acid resistance: pH-sensing, activation by chloride and autoinhibition in GadB.The EMBO journal · 2006Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
3 authors at 1 institution in 1 country.
Funding
Abstract
The two active sites of dimeric 5-aminolevulinate synthase (ALAS), a pyridoxal 5'-phosphate (PLP)-dependent enzyme, are located on the subunit interface with contribution of essential amino acids from each subunit. Linking the two subunits into a single polypeptide chain dimer (2XALAS) yielded an enzyme with an approximate sevenfold greater turnover number than that of wild-type ALAS. Spectroscopic and kinetic properties of 2XALAS were investigated to explore the differences in the coenzyme structure and kinetic mechanism relative to those of wild-type ALAS that confer a more active enzyme. The absorption spectra of both ALAS and 2XALAS had maxima at 410 and 330 nm, with a greater A(410)/A(330) ratio at pH approximately 7.5 for 2XALAS. The 330 nm absorption band showed an intense fluorescence at 385 nm but not at 510 nm, indicating that the 330 nm absorption species is the substituted aldamine rather than the enolimine form of the Schiff base. The 385 nm emission intensity increased with increasing pH with a single pK of approximately 8.5 for both enzymes, and thus the 410 and 330 nm absorption species were attributed to the ketoenamine and substituted aldamine, respectively. Transient kinetic analysis of the formation and decay of the quinonoid intermediate EQ(2) indicated that, although their rates were similar in ALAS and 2XALAS, accumulation of this intermediate was greater in the 2XALAS-catalyzed reaction. Collectively, these results suggest that ketoenamine is the active form of the coenzyme and forms a more prominent coenzyme structure in 2XALAS than in ALAS at pH approximately 7.5.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.