scholarly journals Genetic and Functional Analysis of the Soluble Oxaloacetate Decarboxylase from Corynebacterium glutamicum

2010 ◽  
Vol 192 (10) ◽  
pp. 2604-2612 ◽  
Author(s):  
Simon Klaffl ◽  
Bernhard J. Eikmanns
Keyword(s):  
Specific Activity ◽  
Fold Increase ◽  
Peptide Mass Fingerprinting ◽  
Transcriptional Analysis ◽  
Lysine Production ◽  
Ionization Time ◽  
Peptide Mass ◽  
Methyltransferase Gene ◽  
High Level

ABSTRACT Soluble, divalent cation-dependent oxaloacetate decarboxylases (ODx) catalyze the irreversible decarboxylation of oxaloacetate to pyruvate and CO2. Although these enzymes have been characterized in different microorganisms, the genes that encode them have not been identified, and their functions have been only poorly analyzed so far. In this study, we purified a soluble ODx from wild-type C. glutamicum about 65-fold and used matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) analysis and peptide mass fingerprinting for identification of the corresponding odx gene. Inactivation and overexpression of odx led to an absence of ODx activity and to a 30-fold increase in ODx specific activity, respectively; these findings unequivocally confirmed that this gene encodes a soluble ODx. Transcriptional analysis of odx indicated that there is a leaderless transcript that is organized in an operon together with a putative S-adenosylmethionine-dependent methyltransferase gene. Biochemical analysis of ODx revealed that the molecular mass of the native enzyme is about 62 ± 1 kDa and that the enzyme is composed of two ∼29-kDa homodimeric subunits and has a Km for oxaloacetate of 1.4 mM and a V max of 201 μmol of oxaloacetate converted per min per mg of protein, resulting in a k cat of 104 s−1. Introduction of plasmid-borne odx into a pyruvate kinase-deficient C. glutamicum strain restored growth of this mutant on acetate, indicating that a high level of ODx activity redirects the carbon flux from oxaloacetate to pyruvate in vivo. Consistently, overexpression of the odx gene in an l-lysine-producing strain of C. glutamicum led to accumulation of less l-lysine. However, inactivation of the odx gene did not improve l-lysine production under the conditions tested.

scholarly journals In vivo emergence of high-level resistance during treatment reveals the first identified mechanism of amphotericin B resistance in Candida auris

2021 ◽  
Author(s):  
Jeffrey Michael Rybak ◽  
Katherine S Barker ◽  
Jose F Munoz ◽  
Josie E Parker ◽  
Suhail Ahmad ◽  
...  
Keyword(s):  
Amphotericin B ◽  
Fold Increase ◽  
Multidrug Resistant ◽  
Ergosterol Biosynthesis ◽  
Candida Auris ◽  
Genetic Manipulations ◽  
Methyltransferase Gene ◽  
Significant Step ◽  
High Level

Candida auris has emerged as a healthcare-associated and multidrug-resistant fungal pathogen of great clinical concern. While as much as 50% of C. auris clinical isolates are reported to be resistant to amphotericin B, to date, no mechanisms contributing to this resistance have been identified. We report here mutations in the C. auris sterol-methyltransferase gene, ERG6, as the first identified mechanism of amphotericin B resistance in this emerging pathogen and describe the clinical case in which this high-level amphotericin B resistance was acquired in vivo during therapy. Whole genome sequencing revealed the four C. auris isolates obtained from this single patient case to be genetically related and identified a mutation in ERG6 as being associated with amphotericin B resistance. Cas9-mediated genetic manipulations confirmed this mutation alone to confer a >32-fold increase in amphotericin B resistance, and comprehensive sterol profiling revealed an abrogation of ergosterol biosynthesis and a corresponding accumulation of cholesta-type sterols in isolates and strains harboring the clinically derived ERG6 mutation. Together these findings represent the first significant step forward in the understanding of clinical amphotericin B resistance in C. auris.

scholarly journals Stable isotope labelling in vivo as an aid to protein identification in peptide mass fingerprinting

PROTEOMICS ◽  
2002 ◽  
Vol 2 (2) ◽  
pp. 157-163 ◽  
Author(s):  
Julie M. Pratt ◽  
Duncan H. L. Robertson ◽  
Simon J. Gaskell ◽  
Isabel Riba-Garcia ◽  
Simon J. Hubbard ◽  
...  
Keyword(s):  
Stable Isotope ◽  
Protein Identification ◽  
Peptide Mass Fingerprinting ◽  
Stable Isotope Labelling ◽  
Isotope Labelling ◽  
Peptide Mass

scholarly journals Site-Specific N-Glycosylation on the AAV8 Capsid Protein

Viruses ◽  
2018 ◽  
Vol 10 (11) ◽  
pp. 644 ◽  
Author(s):  
Arya Aloor ◽  
Junping Zhang ◽  
Ebtesam Gashash ◽  
Aishwarya Parameswaran ◽  
Matthew Chrzanowski ◽  
...  
Keyword(s):  
Capsid Protein ◽  
High Resolution Mass Spectrometry ◽  
Genetic Diseases ◽  
Peptide Mass Fingerprinting ◽  
Gene Therapy Vector ◽  
Host Cell Proteins ◽  
Peptide Mass ◽  
293 Cells ◽  
Proteome Discoverer

Adeno associated virus (AAV) is a versatile gene delivery tool, which has been approved as a human gene therapy vector for combating genetic diseases. AAV capsid proteins are the major components that determine the tissue specificity, immunogenicity and in vivo transduction performance of the vector. In this study, the AAV8 capsid glycosylation profile was systemically analyzed by peptide mass fingerprinting utilizing high-resolution mass spectrometry to determine the presence of capsid glycosylation. We identified N-glycosylation on the amino acid N499 of the capsid protein. We characterized the overall sugar profile for vector produced in 293 cells. Multiple N-glycosylated host-cell proteins (HCPs) copurified with AAV8 vectors and were identified by analyzing LC-MS data utilizing a human database and proteome discoverer search engine. The N-glycosylation analysis by MALDI-TOF MS, highlighted the probability of AAV8 interaction with terminal galactosylated N-glycans within the HCPs.

scholarly journals Altered Protein Expression of Streptococcus oralis Cultured at Low pH Revealed by Two-Dimensional Gel Electrophoresis

2001 ◽  
Vol 67 (8) ◽  
pp. 3396-3405 ◽  
Author(s):  
Joanna C. Wilkins ◽  
Karen A. Homer ◽  
David Beighton
Keyword(s):  
Gel Electrophoresis ◽  
Peptide Mass Fingerprinting ◽  
Low Ph ◽  
Ionization Mass ◽  
Two Dimensional ◽  
Two Dimensional Gel Electrophoresis ◽  
Altered Expression ◽  
Streptococcus Oralis ◽  
Peptide Mass

ABSTRACT Streptococcus oralis is the predominant aciduric nonmutans streptococcus isolated from the human dentition, but the role of this organism in the initiation and progression of dental caries has yet to be established. To identify proteins that are differentially expressed by S. oralis growing under conditions of low pH, soluble cellular proteins extracted from bacteria grown in batch culture at pH 5.2 or 7.0 were analyzed by two-dimensional (2-D) gel electrophoresis. Thirty-nine proteins had altered expression at low pH; these were excised, digested with trypsin using an in-gel protocol, and further analyzed by peptide mass fingerprinting using matrix-assisted laser desorption ionization mass spectrometry. The resulting fingerprints were compared with the genomic database forStreptococcus pneumoniae, an organism that is phylogenetically closely related to S. oralis, and putative functions for the majority of these proteins were determined on the basis of functional homology. Twenty-eight proteins were up-regulated following growth at pH 5.2; these included enzymes of the glycolytic pathway (glyceraldehyde-3-phosphate dehydrogenase and lactate dehydrogenase), the polypeptide chains comprising ATP synthase, and proteins that are considered to play a role in the general stress response of bacteria, including the 60-kDa chaperone, Hsp33, and superoxide dismutase, and three distinct ABC transporters. These data identify, for the first time, gene products that may be important in the survival and proliferation of nonmutans aciduric S. oralis under conditions of low pH that are likely to be encountered by this organism in vivo.

scholarly journals The phospholipid-dependence of uridine diphosphate glucuronyltransferase. Effect of protein deficiency on the phospholipid composition and enzyme activity of rat liver microsomal fraction

1974 ◽  
Vol 137 (3) ◽  
pp. 567-574 ◽  
Author(s):  
A. B. Graham ◽  
B. G. Woodcock ◽  
G. C. Wood
Keyword(s):  
Specific Activity ◽  
Phospholipid Composition ◽  
Fold Increase ◽  
Protein Deficiency ◽  
Male Rats ◽  
Striking Difference ◽  
Uridine Diphosphate ◽  
Microsomal Membranes ◽  
Microsomal Phospholipid

After force-feeding a protein-free diet to male rats for 5–7 days a substantial (2.4-fold) increase in the specific activity of the liver microsomal enzyme UDP-glucuronyltransferase (EC 2.4.1.17) was observed. A similar activation of the enzyme occurred when rats were fed on a low-protein (5%, w/w, casein) diet for 60 days. Although both the short- and long-term protein-deficient diets decreased the contents of microsomal protein and phospholipid in liver tissue they did not significantly alter the ratio of these major membrane components. Protein deficiency profoundly altered the phospholipid composition of microsomal membranes. The most striking difference in microsomal phospholipid composition between control and protein-deficient rats was their content of lysophosphatides. Whereas microsomal membranes from protein-deficient rats contained significant proportions of lysophosphatidylcholine and lysophosphatidylethanolamine very little or no lysophosphatides were detected in control preparations. Pretreatment of microsomal fractions from normal rats with phospholipase A markedly increased their UDP-glucuronyltransferase activity as did their pretreatment with lysophosphatidylcholine. It is concluded that the quantities of lysophosphatides present in microsomal membranes from protein-deficient rats were sufficient to have caused the increased UDP-glucuronyltransferase activities of these preparations. Evidence is presented suggesting that these changes in microsomal phospholipid composition and UDP-glucuronyltransferase activity caused by protein deficiency reflect changes that occur in vivo. The possible physiological significance of these findings is discussed.

scholarly journals Identification and Phenotypic Characterization of Sphingomonas wittichii Strain RW1 by Peptide Mass Fingerprinting Using Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry

2005 ◽  
Vol 71 (5) ◽  
pp. 2442-2451 ◽  
Author(s):  
Rolf U. Halden ◽  
David R. Colquhoun ◽  
Eric S. Wisniewski
Keyword(s):  
Mass Spectrometry ◽  
Laser Desorption ◽  
Peptide Mass Fingerprinting ◽  
Phenotypic Characterization ◽  
Laser Desorption Ionization ◽  
Ionization Time ◽  
Flight Mass Spectrometry ◽  
Peptide Mass ◽  
Sphingomonas Wittichii

ABSTRACT Mass spectrometry is a potentially attractive means of monitoring the survival and efficacy of bioaugmentation agents, such as the dioxin-mineralizing bacterium Sphingomonas wittichii strain RW1. The biotransformation activity of RW1 phenotypes is determined primarily by the presence and concentration of the dioxin dioxygenase, an enzyme initiating the degradation of both dibenzo-p-dioxin and dibenzofuran (DF). We explored the possibility of identifying and characterizing putative cultures of RW1 by peptide mass fingerprinting (PMF) targeting this characteristic phenotypic biomarker. The proteome from cells of RW1—grown on various media in the presence and absence of DF—was partially purified, tryptically digested, and analyzed using matrix-assisted laser desorption ionization-time of flight mass spectrometry. Mascot online database queries allowed statistically significant identification of RW1 in disrupted, digested cells (P < 0.01 to 0.05) and in digested whole-cell extracts (P < 0.00001 to 0.05) containing hundreds of proteins, as determined by two-dimensional gel electrophoresis. Up to 14 peptide ions of the alpha subunit of the dioxin dioxygenase (43% protein coverage) were detected in individual samples. A minimum of 107 DF-grown cells was required to identify dioxin degradation-enabled phenotypes. The technique hinges on the detection of multiple characteristic peptides of a biomarker that can reveal at once the identity and phenotypic properties of the microbial host expressing the protein. The results demonstrate the power of PMF of minimally processed microbial cultures as a sensitive and specific technique for the positive identification and phenotypic characterization of certain microorganisms used in biotechnology and bioremediation.

scholarly journals Highly Active and Stable Large Catalase Isolated from a Hydrocarbon Degrading Aspergillus terreus MTCC 6324

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Preety Vatsyayan ◽  
Pranab Goswami
Keyword(s):  
Molecular Mass ◽  
Aspergillus Terreus ◽  
Specific Activity ◽  
Catalytic Efficiency ◽  
Highly Active ◽  
Peptide Mass ◽  
Tandem Mass Spectroscopy ◽  
Isoelectric Ph ◽  
Alkaline Ph Stability ◽  
High Level

A hydrocarbon degrading Aspergillus terreus MTCC 6324 produces a high level of extremely active and stable cellular large catalase (CAT) during growth on n-hexadecane to combat the oxidative stress caused by the hydrocarbon degrading metabolic machinery inside the cell. A 160-fold purification with specific activity of around 66 × 105 U mg−1 protein was achieved. The native protein molecular mass was 368 ± 5 kDa with subunit molecular mass of nearly 90 kDa, which indicates that the native CAT protein is a homotetramer. The isoelectric pH (pI) of the purified CAT was 4.2. BLAST aligned peptide mass fragments of CAT protein showed its highest similarity with the catalase B protein from other fungal sources. CAT was active in a broad range of pH 4 to 12 and temperature 25°C to 90°C. The catalytic efficiency (Kcat/Km) of 4.7 × 108 M−1 s−1 within the studied substrate range and alkaline pH stability (half-life, t1/2 at pH 12~15 months) of CAT are considerably higher than most of the extensively studied catalases from different sources. The storage stability (t1/2) of CAT at physiological pH 7.5 and 4°C was nearly 30 months. The haem was identified as haem b by electrospray ionization tandem mass spectroscopy (ESI-MS/MS).

scholarly journals Purificação e avaliação da interferência de BthMP (uma metaloprotease da peçonha de Bothrops moojeni) na coagulação sanguínea

2016 ◽  
Vol 1 (2) ◽  
pp. 7
Author(s):  
Manuela Andrade Santos ◽  
Luzia Aparecida Pando ◽  
Veridiana De Melo Rodrigues ◽  
Mariana De Souza Castro ◽  
Mário Sérgio Rocha Rocha Gomes
Keyword(s):  
Peptide Mass Fingerprinting ◽  
Maldi Tof ◽  
Peptide Mass ◽  
Sds Page ◽  
Bothrops Moojeni

Neste trabalho relatamos a purificação da metaloprotease BthMP, proveniente da peçonha da serpente Bothrops moojeni. Para a purificação desta protease, utilizaram-se os passos cromatográficos de troca iônica (DEAE-Sepharose) e de exclusão molecular (Sephadex G-75), sendo o produto desses processos uma banda proteica com elevado grau de pureza, visualizada em SDS-PAGE a 14%, denominada BthMP. Esta, por sua vez, quando analisada em MALDI-TOF revelou a massa molecular nativa de 23.050 Da e 23.872 Da na forma reduzida, e a partir dos fragmentos peptídicos obtidos por Peptide Mass Fingerprinting (PMF) em MS (MALDI-TOF/TOF) indicou alta similaridade com a metaloprotease BmooMPα-I. Em termos enzimáticos, BthMP mostrou atividade proteolítica sobre azocaseína e frente ao PMSF e benzamidina, enquanto que esta atividade foi inibida na presença de EDTA, 1,10-fenantrolina e β-mercaptoetanol, sendo portanto uma metaloprotease zinco dependente da classe P-I. Ainda com este propósito, verificou-se sua especificidade enzimática sobre as cadeias Aα e Bβ do fibrinogênio, e também o consumo de fibrinogênio in vivo. Foi constatado ainda sua ação em componentes da cascata de coagulação, devido ao prolongamento do Tempo de Protrombina (TP) e do Tempo de Tromboplastina Parcial ativada (TTPa). Desta forma, a acentuada atividade fibrinogenolítica e o alto consumo de fibrinogênio in vivo são resultados que indicam a ação anticoagulante da BthMP; além do mais, sua capacidade de interferir na cascata de coagulação sugere que esta protease é promissora para futuros estudos que possam indicar um novo modelo de fármaco antitrombótico. https://doi.galoa.com.br/doi/10.17648/jibi-2448-0002-1-2-5128

Restriction of the in vitro and in vivo tyrosine protein kinase activities of pp60c-src relative to pp60v-src

1985 ◽  
Vol 5 (10) ◽  
pp. 2753-2763
Author(s):  
P M Coussens ◽  
J A Cooper ◽  
T Hunter ◽  
D Shalloway
Keyword(s):  
Protein Kinase ◽  
Specific Activity ◽  
Cellular Protein ◽  
Transformed Cells ◽  
Exogenous Substrate ◽  
Tyrosine Protein Kinase ◽  
Substrate Phosphorylation ◽  
High Level

The tyrosine protein kinase activities of pp60c-src and pp60v-src were compared. The activities were qualitatively similar in vitro when the src proteins were bound in an immune complex with monoclonal antibody; both proteins utilized either ATP or GTP as phosphate donors, preferred Mn2+ to Mg2+, and had similar exogenous substrate specificities. The specific activity of pp60c-src was about 10-fold lower than that of pp60v-src for exogenous substrate phosphorylation but was only 1.1- to 2-fold lower than that of pp60v-src for autophosphorylation. Six glycolytic enzymes, including three not previously identified as substrates for pp60src phosphorylation, were phosphorylated by both pp60c-src and pp60v-src. Levels of pp60c-src fourfold higher than the amount of pp60v-src in src-plasmid-transformed cells did not detectably alter the level of phosphotyrosine in cellular proteins, but increasing the expression of pp60c-src another twofold (which induces cells to form foci in monolayer culture (P.J. Johnson, P.M. Coussens, A.V. Danko, and D. Shalloway, Mol. Cell. Biol. 5:1073-1083, 1985) resulted in a threefold increase in the level of cellular protein phosphotyrosine. Immunoprecipitation and analysis of the alkali-stable phosphoproteins by two-dimensional electrophoresis showed that, in contrast to pp60v-src-transformed cells, pp36 and enolase are only weakly phosphorylated in these high-level pp60c-src overexpresser cells. Even allowing for the in vitro differences in specific activities of phosphorylation, these results suggest that the pp60c-src tyrosine protein phosphorylating activity may be restricted relative to that of pp60v-src by additional in vivo mechanisms.

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