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Tokarska-Schlattner M, Zeaiter N, Cunin V, Attia S, Meunier C, Kay L, Achouri A, Hiriart-Bryant E, Couturier K, Tellier C, El Harras A, Elena-Herrmann B, Khochbin S, Le Gouellec A, Schlattner U. Multi-Method Quantification of Acetyl-Coenzyme A and Further Acyl-Coenzyme A Species in Normal and Ischemic Rat Liver. Int J Mol Sci 2023; 24:14957. [PMID: 37834405 PMCID: PMC10573920 DOI: 10.3390/ijms241914957] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 09/29/2023] [Accepted: 09/30/2023] [Indexed: 10/15/2023] Open
Abstract
Thioesters of coenzyme A (CoA) carrying different acyl chains (acyl-CoAs) are central intermediates of many metabolic pathways and donor molecules for protein lysine acylation. Acyl-CoA species largely differ in terms of cellular concentrations and physico-chemical properties, rendering their analysis challenging. Here, we compare several approaches to quantify cellular acyl-CoA concentrations in normal and ischemic rat liver, using HPLC and LC-MS/MS for multi-acyl-CoA analysis, as well as NMR, fluorimetric and spectrophotometric techniques for the quantification of acetyl-CoAs. In particular, we describe a simple LC-MS/MS protocol that is suitable for the relative quantification of short and medium-chain acyl-CoA species. We show that ischemia induces specific changes in the short-chain acyl-CoA relative concentrations, while mild ischemia (1-2 min), although reducing succinyl-CoA, has little effects on acetyl-CoA, and even increases some acyl-CoA species upstream of the tricarboxylic acid cycle. In contrast, advanced ischemia (5-6 min) also reduces acetyl-CoA levels. Our approach provides the keys to accessing the acyl-CoA metabolome for a more in-depth analysis of metabolism, protein acylation and epigenetics.
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Affiliation(s)
- Malgorzata Tokarska-Schlattner
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Nour Zeaiter
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Valérie Cunin
- University Grenoble Alpes, CNRS UMR 5525, Laboratory TIMC—Translational Microbiology, Evolution, Engineering (TREE), Service de Biochimie, Biologie Moléculaire et Toxicologie Environnementale, CHU Grenoble-Alpes, 38058 Grenoble, France; (V.C.); (C.M.); (A.L.G.)
| | - Stéphane Attia
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Cécile Meunier
- University Grenoble Alpes, CNRS UMR 5525, Laboratory TIMC—Translational Microbiology, Evolution, Engineering (TREE), Service de Biochimie, Biologie Moléculaire et Toxicologie Environnementale, CHU Grenoble-Alpes, 38058 Grenoble, France; (V.C.); (C.M.); (A.L.G.)
| | - Laurence Kay
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Amel Achouri
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Edwige Hiriart-Bryant
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Karine Couturier
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Cindy Tellier
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
| | - Abderrafek El Harras
- University Grenoble Alpes, Inserm U1209 and CNRS UMR5309, Institute for Advanced Biosciences (IAB), 38058 Grenoble, France; (A.E.H.); (B.E.-H.); (S.K.)
| | - Bénédicte Elena-Herrmann
- University Grenoble Alpes, Inserm U1209 and CNRS UMR5309, Institute for Advanced Biosciences (IAB), 38058 Grenoble, France; (A.E.H.); (B.E.-H.); (S.K.)
| | - Saadi Khochbin
- University Grenoble Alpes, Inserm U1209 and CNRS UMR5309, Institute for Advanced Biosciences (IAB), 38058 Grenoble, France; (A.E.H.); (B.E.-H.); (S.K.)
| | - Audrey Le Gouellec
- University Grenoble Alpes, CNRS UMR 5525, Laboratory TIMC—Translational Microbiology, Evolution, Engineering (TREE), Service de Biochimie, Biologie Moléculaire et Toxicologie Environnementale, CHU Grenoble-Alpes, 38058 Grenoble, France; (V.C.); (C.M.); (A.L.G.)
| | - Uwe Schlattner
- University Grenoble Alpes, Inserm U1055, Laboratory of Fundamental and Applied Bioenergetics (LBFA), 38058 Grenoble, France; (N.Z.); (S.A.); (L.K.); (A.A.); (E.H.-B.); (K.C.); (C.T.)
- Institut Universitaire de France (IUF), 75231 Paris, France
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Fabris E, Bulfoni M, Nencioni A, Nencioni E. Intra-Laboratory Validation of Alpha-Galactosidase Activity Measurement in Dietary Supplements. Molecules 2021; 26:1566. [PMID: 33809185 PMCID: PMC8000382 DOI: 10.3390/molecules26061566] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/05/2021] [Accepted: 03/09/2021] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Alpha-galactosidase (α-Gal) is an enzyme responsible for the hydrolyzation of glycolipids and glycoprotein commonly found in dietary sources. More than 20% of the general population suffers from abdominal pain or discomfort caused by intestinal gas and by indigested or partially digested food residuals. Therefore, α-Gal is used in dietary supplements to reduce intestinal gases and help complex food digestion. Marketed enzyme-containing dietary supplements must be produced in accordance with the Food and Drug Administration (FDA) regulations for Current Good Manufacturing Practice (cGMPs). AIM in this work we illustrated the process used to develop and validate a spectrophotometric enzymatic assay for α-Gal activity quantification in dietary supplements. METHODS The validation workflow included an initial statistical-phase optimization of materials, reagents, and conditions, and subsequently a comparative study with another fluorimetric assay. A final validation of method performance in terms of specificity, linearity, accuracy, intermediate-precision repeatability, and system precision was then executed. RESULTS AND CONCLUSIONS The proven method achieved good performance in the quantitative determination of α-Gal activity in commercial food supplements in accordance with the International Council for Harmonisation of Technical Requirements for Pharmaceuticals (ICH) guidelines and is suitable as a rapid in-house quality control test.
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Affiliation(s)
- Elena Fabris
- Biofarma Group Srl, Via Castelliere 2, Mereto di Tomba, 33036 Udine, Italy;
| | - Michela Bulfoni
- Institute of Pathology Department of Medicine, University of Udine, 33100 Udine, Italy;
| | - Alessandro Nencioni
- IBSA Institut Biochimique SA, Via del Piano29, CH-6915 Pambio Noranco, Switzerland;
| | - Emanuele Nencioni
- Biofarma Group Srl, Via Castelliere 2, Mereto di Tomba, 33036 Udine, Italy;
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Dettori MA, Fabbri D, Dessì A, Dallocchio R, Carta P, Honisch C, Ruzza P, Farina D, Migheli R, Serra PA, Pantaleoni RA, Fois X, Rocchitta G, Delogu G. Synthesis and Studies of the Inhibitory Effect of Hydroxylated Phenylpropanoids and Biphenols Derivatives on Tyrosinase and Laccase Enzymes. Molecules 2020; 25:E2709. [PMID: 32545293 PMCID: PMC7321210 DOI: 10.3390/molecules25112709] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 12/12/2022] Open
Abstract
The impaired activity of tyrosinase and laccase can provoke serious concerns in the life cycles of mammals, insects and microorganisms. Investigation of inhibitors of these two enzymes may lead to the discovery of whitening agents, medicinal products, anti-browning substances and compounds for controlling harmful insects and bacteria. A small collection of novel reversible tyrosinase and laccase inhibitors with a phenylpropanoid and hydroxylated biphenyl core was prepared using naturally occurring compounds and their activity was measured by spectrophotometric and electrochemical assays. Biosensors based on tyrosinase and laccase enzymes were constructed and used to detect the type of protein-ligand interaction and half maximal inhibitory concentration (IC50). Most of the inhibitors showed an IC50 in a range of 20-423 nM for tyrosinase and 23-2619 nM for laccase. Due to the safety concerns of conventional tyrosinase and laccase inhibitors, the viability of the new compounds was assayed on PC12 cells, four of which showed a viability of roughly 80% at 40 µM. In silico studies on the crystal structure of laccase enzyme identified a hydroxylated biphenyl bearing a prenylated chain as the lead structure, which activated strong and effective interactions at the active site of the enzyme. These data were confirmed by in vivo experiments performed on the insect model Tenebrio molitur.
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Affiliation(s)
- Maria Antonietta Dettori
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
| | - Davide Fabbri
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
| | - Alessandro Dessì
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
| | - Roberto Dallocchio
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
| | - Paola Carta
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
| | - Claudia Honisch
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, 35131 Padova, Italy; (C.H.); or (P.R.)
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 35131 Padova, Italy
| | - Paolo Ruzza
- Dipartimento di Scienze Chimiche, Università degli Studi di Padova, 35131 Padova, Italy; (C.H.); or (P.R.)
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 35131 Padova, Italy
| | - Donatella Farina
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università degli Studi, 07100 Sassari, Italy; (D.F.); (R.M.); (P.A.S.)
| | - Rossana Migheli
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università degli Studi, 07100 Sassari, Italy; (D.F.); (R.M.); (P.A.S.)
| | - Pier Andrea Serra
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università degli Studi, 07100 Sassari, Italy; (D.F.); (R.M.); (P.A.S.)
| | - Roberto A. Pantaleoni
- Istituto di Ricerca sugli Ecosistemi Terrestri, Consiglio Nazionale Ricerca, 07100 Sassari, Italy; (R.A.P.); (X.F.)
- Dipartimento di Agraria, Università degli Studi, 07100 Sassari, Italy
| | - Xenia Fois
- Istituto di Ricerca sugli Ecosistemi Terrestri, Consiglio Nazionale Ricerca, 07100 Sassari, Italy; (R.A.P.); (X.F.)
| | - Gaia Rocchitta
- Dipartimento di Scienze Mediche, Chirurgiche e Sperimentali, Università degli Studi, 07100 Sassari, Italy; (D.F.); (R.M.); (P.A.S.)
| | - Giovanna Delogu
- Istituto di Chimica Biomolecolare, Consiglio Nazionale Ricerche, 07100 Sassari, Italy; (M.A.D.); (D.F.); (A.D.); (R.D.); (P.C.)
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Ramesh KSV, Swetha P, Mohan Kumar P, Sruthima NVS, Naresh Kumar C. Estimation of superoxide dismutase levels in saliva and gingival crevicular fluid among smokers and non-smokers in periodontitis patients - An Observational Study. Niger Med J 2019; 60:133-137. [PMID: 31543565 PMCID: PMC6737800 DOI: 10.4103/nmj.nmj_56_19] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Background: Smoking, which is an important risk factor for periodontitis, induces oxidative stress in the body and causes an imbalance between reactive oxygen species (ROS) and antioxidants, such as superoxide dismutase (SOD). The present study was done to quantify and compare the level of SOD enzyme levels in gingival crevicular fluid (GCF) and saliva among smokers and nonsmokers. Methodology: One hundred and thirty-five individuals in the age range of 20–55 years, including 45 light smokers, 45 heavy smokers, and 45 nonsmokers (controls), were selected and the clinical parameters recorded were plaque index, probing depth, and attachment loss. Smokers were divided into light smokers (<10 cigarettes/day) and heavy smokers (>10 cigarettes/day) and into three subgroups: healthy, mild periodontitis, and moderate periodontitis. GCF and saliva samples were collected then SOD levels were analyzed using spectrophotometric assay. Results: The mean levels of SOD in the GCF and saliva of smokers were decreased compared to controls. Intra- and inter-group analyses showed a significant reduction in the levels of SOD in the GCF and saliva of heavy smokers compared to light smokers and the control group. Conclusions: There was a progressive reduction in SOD levels from healthy nonsmokers to light smokers to heavy smokers.
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Affiliation(s)
- K S V Ramesh
- Department of Periodontics, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
| | - P Swetha
- Department of Oral Pathology, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
| | - P Mohan Kumar
- Department of Periodontics, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
| | - N V S Sruthima
- Department of Periodontics, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
| | - C Naresh Kumar
- Department of Periodontics, Vishnu Dental College, Bhimavaram, Andhra Pradesh, India
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Demers-Mathieu V, Nielsen SD, Underwood MA, Borghese R, Dallas DC. Changes in Proteases, Antiproteases, and Bioactive Proteins From Mother's Breast Milk to the Premature Infant Stomach. J Pediatr Gastroenterol Nutr 2018; 66:318-24. [PMID: 28906320 DOI: 10.1097/MPG.0000000000001719] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVE Our previous studies suggested that human milk proteases begin to hydrolyze proteins in the mammary gland and continue within the term infant' stomach. No research has measured milk protease and pepsin activity in the gastric aspirates of preterm infants after human milk feeding. This study investigated how the concentrations of human milk proteases and protease inhibitors changed in the premature infant stomach. METHODS Human milk and infant gastric samples were collected from 18 preterm-delivering mother-infant pairs (24-32 week gestational age). Paired human milk and gastric samples were collected across postnatal age (2-47 days). Protease concentrations were determined by spectrophotometric or fluorometric assays, and the concentrations of protease inhibitors and bioactive proteins were determined by enzyme-linked immunosorbent assay. Paired t tests were applied to compare enzymes, antiproteases, and bioactive proteins between human milk and gastric samples. RESULTS Our study reveals that although human milk proteases, including carboxypeptidase B2, kallikrein, plasmin, cathepsin D, elastase, thrombin, and cytosol aminopeptidase, are present in the preterm infant stomach, only plasmin and cathepsin D can actively hydrolyze proteins at gastric pH. Enzyme-linked immunosorbent assay and peptidomic evidence suggest that all milk antiproteases as well as lactoferrin and immunoglobulin A are partially digested in the preterm stomach. CONCLUSIONS Most human milk proteases are active in milk but not at preterm infant gastric pH. Only cathepsin D and plasmin have potential to continue degrading milk proteins within the preterm infant stomach.
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Guo S, Liang Y, Murphy SF, Huang A, Shen H, Kelly DF, Sobrado P, Sheng Z. A rapid and high content assay that measures cyto-ID-stained autophagic compartments and estimates autophagy flux with potential clinical applications. Autophagy 2016; 11:560-72. [PMID: 25714620 PMCID: PMC4502761 DOI: 10.1080/15548627.2015.1017181] [Citation(s) in RCA: 103] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The lack of a rapid and quantitative autophagy assay has substantially hindered the development and implementation of autophagy-targeting therapies for a variety of human diseases. To address this critical issue, we developed a novel autophagy assay using the newly developed Cyto-ID fluorescence dye. We first verified that the Cyto-ID dye specifically labels autophagic compartments with minimal staining of lysosomes and endosomes. We then developed a new Cyto-ID fluorescence spectrophotometric assay that makes it possible to estimate autophagy flux based on measurements of the Cyto-ID-stained autophagic compartments. By comparing to traditional autophagy approaches, we found that this assay yielded a more sensitive, yet less variable, quantification of the stained autophagic compartments and the estimate of autophagy flux. Furthermore, we tested the potential application of this autophagy assay in high throughput research by integrating it into an RNA interference (RNAi) screen and a small molecule screen. The RNAi screen revealed WNK2 and MAP3K6 as autophagy-modulating genes, both of which inhibited the MTOR pathway. Similarly, the small molecule screen identified sanguinarine and actinomycin D as potent autophagy inducers in leukemic cells. Moreover, we successfully detected autophagy responses to kinase inhibitors and chloroquine in normal or leukemic mice using this assay. Collectively, this new Cyto-ID fluorescence spectrophotometric assay provides a rapid, reliable quantification of autophagic compartments and estimation of autophagy flux with potential applications in developing autophagy-related therapies and as a test to monitor autophagy responses in patients being treated with autophagy-modulating drugs.
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Key Words
- 3-MA, 3-methyladenine
- Cyto-ID
- FBS, fetal bovine serum
- GFP, green fluorescent protein
- LAMP1, lysosomal-associated membrane protein 1
- MAP1LC3B/LC3B, microtubule-associated protein 1 light chain 3 beta
- MAP3K6, mitogen-activated protein kinase kinase kinase 6
- MDC, monodansylcadaverine
- MTOR, mechanistic target of rapamycin
- NS, nonsilencing
- RAB5A, member RAS oncogene family
- RNA interference screen
- RNAi, RNA interference
- SQSTM1, sequestosome 1
- WNK2, WNK lysine deficient protein kinase 2
- autophagy
- autophagy flux
- autophagy response
- mRFP, monomeric red fluorescent protein
- shRNA, short-hairpin RNA
- small molecule screen
- spectrophotometric assay
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Affiliation(s)
- Sujuan Guo
- a Virginia Tech Carilion Research Institute ; Roanoke , VA USA
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Ahmad I, Anwar Z, Iqbal K, Ali SA, Mirza T, Khurshid A, Khurshid A, Arsalan A. Effect of acetate and carbonate buffers on the photolysis of riboflavin in aqueous solution: a kinetic study. AAPS PharmSciTech 2014; 15:550-9. [PMID: 24504494 PMCID: PMC4037473 DOI: 10.1208/s12249-013-0067-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2013] [Accepted: 12/03/2013] [Indexed: 11/30/2022] Open
Abstract
The photolysis of riboflavin (RF) in the presence of acetate buffer (pH 3.8-5.6) and carbonate buffer (pH 9.2-10.8) has been studied using a multicomponent spectrophotometric method for the simultaneous assay of RF and its photoproducts. Acetate and carbonate buffers have been found to catalyze the photolysis reaction of RF. The apparent first-order rate constants for the acetate-catalyzed reaction range from 0.20 to 2.86 × 10(-4) s(-1) and for the carbonate-catalyzed reaction from 3.33 to 15.89 × 10(-4) s(-1). The second-order rate constants for the interaction of RF with the acetate and the carbonate ions range from 2.04 to 4.33 × 10(-4) M(-1) s(-1) and from 3.71 to 11.80 × 10(-4) M(-1) s(-1), respectively. The k-pH profile for the acetate-catalyzed reaction is bell shaped and for the carbonate-catalyzed reaction a steep curve. Both HCO3(-) and CO3(2-) ions are involved in the catalysis of the photolysis reaction in alkaline solution. The rate constants for the HCO3(-) and CO3(2-) ions catalyzed reactions are 0.72 and 1.38 × 10(-3) M(-1) s(-1), respectively, indicating a major role of CO3(2-) ions in the catalysis reaction. The loss of RF fluorescence in acetate buffer suggests an interaction between RF and acetate ions to promote the photolysis reaction. The optimum stability of RF solutions is observed in the pH range 5-6, which is suitable for pharmaceutical preparations.
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Affiliation(s)
- Iqbal Ahmad
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Zubair Anwar
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Kefi Iqbal
- />Baqai Dental College, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Syed Abid Ali
- />HEJ Research Institute of Chemistry, University of Karachi, Karachi, 75270 Pakistan
| | - Tania Mirza
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Adeela Khurshid
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Aqeela Khurshid
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Adeel Arsalan
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
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Ahmad I, Qadeer K, Iqbal K, Ahmed S, Sheraz MA, Ali SA, Mirza T, Hafeez A. Correction for irrelevant absorption in multicomponent spectrophotometric assay of riboflavin, formylmethylflavin, and degradation products: kinetic applications. AAPS PharmSciTech 2013; 14:1101-7. [PMID: 23821430 PMCID: PMC3755170 DOI: 10.1208/s12249-013-9998-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2013] [Accepted: 06/17/2013] [Indexed: 11/30/2022] Open
Abstract
In the spectrophotometric assay of multicomponent systems involved in drug degradation studies, some minor or unknown degradation products may be present. These products may interfere in the assay and thus invalidate the results due to their absorption in the range of analytical wavelengths. This interference may be eliminated by the application of an appropriate correction procedure to obtain reliable data for kinetic treatment. The present study is based on the application of linear and non-linear irrelevant absorption corrections in the multicomponent spectrophotometric assay of riboflavin and formylmethylflavin during the photolysis and hydrolysis studies. The correction procedures take into account the interference caused by minor or unknown products and have shown considerable improvement in the assay data in terms of the molar balance. The treatment of the corrected data has led to more accurate kinetic results in degradation studies.
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Affiliation(s)
- Iqbal Ahmad
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Kiran Qadeer
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Kefi Iqbal
- />Department of Material Science, Baqai Dental College, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Sofia Ahmed
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Muhammad Ali Sheraz
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Syed Abid Ali
- />HEJ Research Institute of Chemistry, University of Karachi, Karachi, 75270 Pakistan
| | - Tania Mirza
- />Baqai Institute of Pharmaceutical Sciences, Baqai Medical University, Toll Plaza, Super Highway, Gadap Road, Karachi, 74600 Pakistan
| | - Ambreen Hafeez
- />Department of Biochemistry, Dow University of Health Sciences, Ojha Campus, Karachi, 75200 Pakistan
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Libertino S, Aiello V, Scandurra A, Renis M, Sinatra F. Immobilization of the Enzyme Glucose Oxidase on Both Bulk and Porous SiO₂ Surfaces. Sensors (Basel) 2008; 8:5637-5648. [PMID: 27873833 PMCID: PMC3705523 DOI: 10.3390/s8095637] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/06/2008] [Revised: 08/26/2008] [Accepted: 09/10/2008] [Indexed: 11/16/2022]
Abstract
Silicon dioxide surfaces, both bulk and porous, were used to anchor the enzyme glucose oxidase. The immobilization protocol was optimized and the samples characterized using X-ray Photoelectron Spectroscopy, Energy Dispersive X-rays coupled to scanning electron microscopy and enzymatic activity measurements. We show that a uniform layer was obtained by activating the oxide before immobilization. X-ray Photoelectron Spectroscopy measurements carried out on bulk oxide showed that the silicon substrate signal was fully screened after the enzyme deposition showing the absence of uncovered surface regions. The enzyme presence was detected monitoring both the C 1s and N 1s signals. Finally, enzymatic activity measurements confirmed that the glucose oxidase activity was preserved after immobilization and maintained after three months of shelf life if the sample was properly stored. The importance of using porous silicon oxide to maximize the surface area was also evidenced.
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Affiliation(s)
| | - Venera Aiello
- Università degli Studi di Catania, Dipartimento di Chimica Biologica, Chimica Medica e Biologia Molecolare, Catania, Italy.
- Università degli Studi di Catania, Dipartimento di Scienze Biomediche, Catania, Italy.
| | - Antonino Scandurra
- Laboratorio Superfici e Interfasi (SUPERLAB), Consorzio Catania Ricerche, Catania, Italy.
| | - Marcella Renis
- Università degli Studi di Catania, Dipartimento di Chimica Biologica, Chimica Medica e Biologia Molecolare, Catania, Italy.
| | - Fulvia Sinatra
- Università degli Studi di Catania, Dipartimento di Scienze Biomediche, Catania, Italy.
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Li Y, Schellhorn HE. Rapid kinetic microassay for catalase activity. J Biomol Tech 2007; 18:185-187. [PMID: 17916790 PMCID: PMC2062561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Catalase is a commonly assayed enzyme found in many bacteria and eukaryotes. In this report, we examined the applicability of a kinetic microassay to quantify catalase from two different sources. The assay was found to be linear over a wide range (0.1-1.0 units), but was limited at high values (>1 unit) by oxygen evolution. Nonetheless, the microassay allows simultaneous evaluation of many samples (up to 96) in a short time (<5 min) and is thus well-suited to applications, such as high-throughput screening, where many parallel assays are required.
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Affiliation(s)
| | - Herb E. Schellhorn
- Address correspondence and reprint requests to: Herb E. Schellhorn, Life Sciences Building 433, 1280 Main Street West, Hamilton, ON Canada L8S 4K1 (phone: 905-525-9140 ext. 27316; fax: 905-522-6066;
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