the branch of biochemistry dealing with the chemical nature and biological activity of enzymes
English Journal
Flavin dependent monooxygenases.
Huijbers MM1, Montersino S1, Westphal AH1, Tischler D2, van Berkel WJ3.Author information 1Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.2Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands; Interdisciplinary Ecological Center, TU Bergakademie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany.3Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands. Electronic address: willem.vanberkel@wur.nl.AbstractFlavin-dependent monooxygenases catalyze a wide variety of chemo-, regio- and enantioselective oxygenation reactions. As such, they are involved in key biological processes ranging from catabolism, detoxification and biosynthesis, to light emission and axon guidance. Based on fold and function, flavin-dependent monooxygenases can be distributed into eight groups. Groups A and B comprise enzymes that rely on NAD(P)H as external electron donor. Groups C-F are two-protein systems, composed of a monooxygenase and a flavin reductase. Groups G and H comprise internal monooxygenases that reduce the flavin cofactor through substrate oxidation. Recently, many new flavin-dependent monooxygenases have been discovered. In addition to posing basic enzymological questions, these proteins attract attention of pharmaceutical and fine-chemical industries, given their importance as regio- and enantioselective biocatalysts. In this review we present an update of the classification of flavin-dependent monooxygenases and summarize the latest advances in our understanding of their catalytic and structural properties.
Archives of biochemistry and biophysics.Arch Biochem Biophys.2014 Feb 15;544C:2-17. doi: 10.1016/j.abb.2013.12.005. Epub 2013 Dec 17.
Flavin-dependent monooxygenases catalyze a wide variety of chemo-, regio- and enantioselective oxygenation reactions. As such, they are involved in key biological processes ranging from catabolism, detoxification and biosynthesis, to light emission and axon guidance. Based on fold and function, flav
A study of 133 Chinese children with mitochondrial respiratory chain complex I deficiency.
Ma YY, Wu TF, Liu YP, Wang Q, Li XY, Ding Y, Song JQ, Yang YL, Zou LP.Author information Department of Pediatrics, Chinese Liberation Army General Hospital, Beijing, China.AbstractTo investigate the clinical, enzymological and mitochondrial gene profiles of complex I deficiency in Chinese, clinical and laboratory data of the patients (79 boys, 54 girls) were retrospectively assessed. Activities of mitochondrial respiratory chain complexes in peripheral leucocytes were spectrophotometrically measured. The entire mitochondrial DNA (mtDNA) sequence was analyzed in 62 patients. Restriction fragment length polymorphism and gene sequencing analyses were performed in 15 families. 91 patients had isolated complex I deficiency; 42 had combined deficiencies of complex I and other complexes. The main clinical presentations were neuromuscular disorders (107 patients) and non-neurological dysfunction (hepatopathy, renal damage and cardiomyopathy; 26 patients). In 32 of 62 patients who underwent mtDNA sequencing, 24 mutations were identified in 15 mitochondrial genes. The 12338 T > C, 4833 A > G and 14502T>C mutations were found in 12.9%, 11.3% and 4.8% patients, respectively. Seven patients had multiple mutations. Three novel mutations were identified. Chinese patients with complex I deficiency presented heterogeneous phenotypes and genotypes. Twenty-four mutations were identified in 15 mitochondrial genes in 51.6% patients. mtDNA mutations were more common in isolated complex I deficiency than in combined complex deficiencies. The 12338 T > C, 4833 A > G and 14502T>C mutations were common.
Clinical genetics.Clin Genet.2014 Feb 6. doi: 10.1111/cge.12356. [Epub ahead of print]
To investigate the clinical, enzymological and mitochondrial gene profiles of complex I deficiency in Chinese, clinical and laboratory data of the patients (79 boys, 54 girls) were retrospectively assessed. Activities of mitochondrial respiratory chain complexes in peripheral leucocytes were spectro
The ABC-F protein EttA gates ribosome entry into the translation elongation cycle.
Boël G1, Smith PC2, Ning W3, Englander MT4, Chen B5, Hashem Y6, Testa AJ5, Fischer JJ7, Wieden HJ8, Frank J9, Gonzalez RL Jr3, Hunt JF1.Author information 11] Department of Biological Sciences, Columbia University, New York, New York, USA. [2] Northeast Structural Genomics Consortium, Columbia University, New York, New York, USA.21] Department of Biological Sciences, Columbia University, New York, New York, USA. [2].3Department of Chemistry, Columbia University, New York, New York, USA.41] Department of Chemistry, Columbia University, New York, New York, USA. [2] Integrated Program in Cellular, Molecular and Biomedical Studies, Columbia University, Medical Center, New York, New York, USA. [3].5Department of Biological Sciences, Columbia University, New York, New York, USA.61] Department of Biochemistry, Columbia University Medical Center, New York, New York, USA. [2] Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York, USA.71] Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada. [2].8Department of Chemistry and Biochemistry, University of Lethbridge, Lethbridge, Alberta, Canada.91] Department of Biological Sciences, Columbia University, New York, New York, USA. [2] Department of Biochemistry, Columbia University Medical Center, New York, New York, USA. [3] Howard Hughes Medical Institute, Columbia University Medical Center, New York, New York, USA.AbstractABC-F proteins have evaded functional characterization even though they compose one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongation cycle through a nucleotide-dependent interaction sensitive to ATP/ADP ratio. Accordingly, we rename this protein energy-dependent translational throttle A (EttA). We determined the crystal structure of Escherichia coli EttA and used it to design mutants for biochemical studies including enzymological assays of the initial steps of protein synthesis. These studies suggest that EttA may regulate protein synthesis in energy-depleted cells, which have a low ATP/ADP ratio. Consistently with this inference, EttA-deleted cells exhibit a severe fitness defect in long-term stationary phase. These studies demonstrate that an ABC-F protein regulates protein synthesis via a new mechanism sensitive to cellular energy status.
ABC-F proteins have evaded functional characterization even though they compose one of the most widely distributed branches of the ATP-binding cassette (ABC) superfamily. Herein, we demonstrate that YjjK, the most prevalent eubacterial ABC-F protein, gates ribosome entry into the translation elongat
Enzymological manipulations (calcium-depletion, a range of chloride-depletion methods and anion replacements, NH3- and NO-binding, and combinations of these treatments) will be applied to PSII cores and these will be ...
Enzymological manipulations (calcium-depletion, a range of chloride-depletion methods and anion replacements, NH3- and NO-binding, and combinations of these treatments) will be applied to PSII cores and these will be ...