Riboflavin is a constituent of coenzyme, FMN, FAD and its content varies according to the physiological and nutritional status. However, the measurement of its content is so disputable that a new technique to determine its content has been developed, done by determination of glutathione reductase activity in red blood cell hemolysate. With this technique, the effect of various anesthetic agents (ether, halothane, tetracaine) upon riboflavin metabolism has been studied by the authors. In conclusion, the effects of anesthetics upon riboflavin metabolism are insignificant.
Anesthetics ; Erythrocytes* ; Flavin Mononucleotide ; Flavin-Adenine Dinucleotide ; Glutathione Reductase ; Glutathione* ; Halothane ; Metabolism ; Nutritional Status ; Riboflavin

Flavoproteins are proteins that contain a nucleic acid derivative of riboflavin: flavin adenine dinucleotide (FAD) or flavin mononucleotide (FMN). Flavoproteins are involved in a wide array of biological processes, such as photosynthesis, DNA repair and natural product biosynthesis. It should be noted that 5%-10% of flavoproteins have a covalently linked flavin prosthetic group. Such covalent linkages benefit the holoenzyme in several ways including improving the stability and catalytic potency. During the past decade, significant progress has been made in covalent flavoproteins, especially with respect to enzyme-dependent biogenesis and discovery of novel linkage types. The present review gives a condensed overview of investigations published from March 2009 to December 2021, with emphasis on the discovery, biogenesis and their catalytic role in natural product biosynthesis.
Flavoproteins/metabolism* ; Flavin-Adenine Dinucleotide/metabolism* ; Flavin Mononucleotide/metabolism* ; Riboflavin ; Biological Products

No abstract available.
Multiple Acyl Coenzyme A Dehydrogenase Deficiency*

The redox biosynthesis system has important applications in green biomanufacturing of chiral compounds. Formate dehydrogenase (FDH) catalyzes the oxidation of formate into carbon dioxide, which is associated with the reduction of NAD(P)⁺ into NAD(P)H. Due to this property, FDH is used as a crucial enzyme in the redox biosynthesis system for cofactor regeneration. Nevertheless, the application of natural FDH in industrial production is hampered by low catalytic efficiency, poor stability, and inefficient coenzyme utilization. This review summarized the structural characteristics and catalytic mechanism of FDH, as well as the advances in protein engineering of FDHs toward improved enzyme activity, catalytic efficiency, stability and coenzyme preference. The applications of using FDH as a coenzyme regeneration system for green biomanufacturing of chiral compounds were summarized.
Catalysis ; Coenzymes/metabolism* ; Formate Dehydrogenases/metabolism* ; NAD/metabolism* ; Protein Engineering

The xylose reductase of Pichia stipitis is one of the most important enzymes. It can be used to build up recombinant Saccharomyces cerevisiae strain for utilizing xylose and producing ethanol. Intercellular redox imbalance caused by NADPH preference over NADH for Pichia stipitis xylose reductase (PsXR) has been considered to be one of the main factors for poor ethanol productivity. Some key amino acids of PsXR, which affect the activity or coenzyme preference, were investigated in our previous study. In this study, Lys21 were rational designed for site-directed mutagenesis to alter coenzyme specificity of PsXR from NADPH and NADH into single NADH. The wild gene and mutagenesis genes were ligated into pET28b, and were transferred into E.coli BL21(DE3). After induced by IPTG, the xylose reductases were purified. Purified mutants K21A (Lys21-->Ala), K21R(Lys21-->Arg) were characterized by steady-state kinetic analysis. The results showed that the coenzyme dependence of K21A was completely reversed to NADH.
Aldehyde Reductase ; metabolism ; Amino Acid Substitution ; genetics ; Coenzymes ; pharmacology ; Escherichia coli ; genetics ; metabolism ; Ethanol ; pharmacology ; Lysine ; genetics ; Mutagenesis, Site-Directed ; NAD ; metabolism ; NADP ; metabolism ; Pichia ; chemistry ; genetics ; metabolism ; Recombinant Proteins ; biosynthesis ; genetics ; metabolism ; Recombination, Genetic ; Xylose ; pharmacology

PURPOSE: We have done this retrospective study to know the relative incidences and clinical manifestations of organic acidopathies in Korea. METHODS: The results of quantitative organic acid analysis of 1,125 samples of 712 patients, referred from Jul. 1997 to Jun. 2000, were analyzed retrospectively according to four age groups (-2 mon, 3 mon-2 year, 3 years-12 years, over 12 years) and major clinical manifestations. Quantification of 83 organic acids was done with gas chromatography and mass spectrometry(GC/MS). RESULTS: We diagnosed 214 patients with 27 diseases of organic acid metabolism during this study period. Diseases found more than 10 cases are cytosolic 3-ketothiolase deficiency, mitochondrial repsiratory chain disorders, PDHC deficiency, glutaric aciduria type II and propionic aciduria. Other diseases were diagnosed in less than 10 cases, mostly one or two cases during this study period. Most of the patients had some symptoms of neurological dysfunction such as seizure activity(195 patients), developmental delay(122), mental retardation(99), hypotonia(84), movement disorders(81) and vomiting(68). CONCLUSION: Though the incidence of individual organic acidemia is low, the overall incidence of organic acidemia as a whole seems to be relatively high in Korea. Most of the patients showed some signs of neurological dysfunction.
Acetyl-CoA C-Acyltransferase ; Chromatography, Gas ; Cytosol ; Humans ; Incidence ; Korea* ; Metabolism ; Multiple Acyl Coenzyme A Dehydrogenase Deficiency ; Propionic Acidemia ; Pyruvate Dehydrogenase Complex Deficiency Disease ; Retrospective Studies ; Seizures

Since we started organic acid analysis in July 1997, we have collected data about organic acidemias in Korea. The data presented herein constitute our 3 years experience in organic acid analysis. We have collected 712 samples from major university hospitals in all over Korea, which are large enough for relatively accurate estimation of incidence of organic acid disorders. We used solvent extraction method with ethylacetate, MSTFA for derivatization and simultaneously quantitation of 83 organic acids. Out of 712 patients sample, 498 samples (70%) showed no evidence of organic acid abnormalities. Out of the 214 remaining samples, we found very diverse disorders such as methylmalonic aciduria (6), propionic aciduria (10), biotinidase deficiency (6), maple syrup urine disease (3), isovaleric aciduria (4), tyrosinemia type II (4), tyrosinemia type IV (1), glutaric aciduria type I (1), glutaric aciduria type II (22), 3-methylglutaconic aciduria type I (3), 3-methylglutaconic aciduria type III (7), HMG-CoA lyase deficiency (1), hyperglyceroluria (2), cytosolic 3-ketothiolase deficiency (55), mitochondrial 3-ketothiolase deficiency (3), 3-hydroxyisobutyric aciduria (2), L-2-hydroxyglutaric aciduria (2), fumaric aciduria (2), lactic aciduria with combined elevation of pyruvate (most likely PDHC deficiency) (28), lactic aciduria without combined elevation of pyruvate (most likely mitochondrial respiratory chain disorders) (35), SCAD deficiency (3), MCAD deficiency (1), 3-methylcrotonylglycineuria (1), orotic aciduria (most likely urea cycle disorders) (7) and 2-methylbranched chain acyl-CoA dehydrogenase deficiency (1). In conclusion, although the incidence of individual organic acidemia is low, the incidence of overall organic acidemia is relatively high in Korea. Most of the patients showed some signs of neurological dysfunction. Therefore, organic acid analysis should be included in the diagnostic work up of all neurological dysfunctions.
Acetyl-CoA C-Acyltransferase ; Acyl-CoA Dehydrogenase ; Biotinidase Deficiency ; Cytosol ; Electron Transport ; Hospitals, University ; Humans ; Incidence ; Korea* ; Maple Syrup Urine Disease ; Multiple Acyl Coenzyme A Dehydrogenase Deficiency ; Propionic Acidemia ; Pyruvic Acid ; Tyrosinemias ; Urea

Two photon fluorescence microscopy and the numerous technical advances to it have served as valuable tools in biomedical research. The fluorophores (exogenous or endogenous) absorb light and emit lower energy photons than the absorption energy and the emission (fluorescence) signal is measured using a fluorescence decay graph. Additionally, high spatial resolution images can be acquired in two photon fluorescence lifetime imaging (2P-FLIM) with improved penetration depth which helps in detection of fluorescence signal in vivo. 2P-FLIM is a non-invasive imaging technique in order to visualize cellular metabolic, by tracking intrinsic fluorophores present in it, such as nicotinamide adenine dinucleotide, flavin adenine dinucleotide and tryptophan etc. 2P-FLIM of these molecules enable the visualization of metabolic alterations, non-invasively. This comprehensive review discusses the numerous applications of 2P-FLIM towards cancer, neuro-degenerative, infectious diseases, and wound healing.
Absorption ; Communicable Diseases ; Flavin-Adenine Dinucleotide ; Fluorescence ; Microscopy, Fluorescence ; NAD ; Photons ; Tryptophan ; Wound Healing

Mitochondrial 3-hydroxy-3-methylglutaryl CoA synthase deficiency (HMCSD) is caused by HMGCS2 gene mutation. This paper reports the clinical and genetic features of an infant with this disease. The 8-month-old female infant was admitted to the hospital with diarrhea for 1 week and fever and convulsion for 1 day. The child presented with seizures, acidosis, hypoglycemia, abnormal liver function, myocardial injury and coagulation dysfunction. The new homozygous mutation c.1502G>A(p.R501Q) in the HMGCS2 gene was found in the infant by genetic testing. The mutant gene was found to be harmful by bioinformatics software analysis. Urine organic acid analysis indicated that 4-hydroxy-6-methyl-2-pyranone was significantly increased, which was consistent with the results of genetic testing. The infant was definitely diagnosed with HMCSD.
Acyl Coenzyme A ; Female ; Humans ; Hypoglycemia ; Infant ; Mitochondria ; Mutation

Raspberry ketones have important therapeutic properties such as anti-influenza and prevention of diabetes. In order to obtain raspberry ketone from Chlamydomonas reinhardtii, two enzymes catalyzing the last two steps of raspberry ketone synthesis, i.e. 4-coumaryl-CoA ligase (4CL) and polyketide synthase (PKS1), were fused using a glycine-serine-glycine (GSG) tripeptide linker to construct an expression vector pChla-4CL-PKS1. The fusion gene 4CL-PKS1 driven by a PSAD promoter was transformed into a wild-type (CC125) and a cell wall-deficient C. reinhardtii (CC425) by electroporation. The results showed the recombinant C. reinhardtii strain CC125 and CC425 with 4CL-PKS1 produced raspberry ketone at a level of 6.7 μg/g (fresh weight) and 5.9 μg/g (fresh weight), respectively, both were higher than that of the native raspberry ketone producing plants (2-4 μg/g).
Acyl Coenzyme A ; Butanones ; Chlamydomonas reinhardtii/genetics* ; Ligases ; Polyketide Synthases