scholarly journals Biosynthesis of Chloro-β-Hydroxytyrosine, a Nonproteinogenic Amino Acid of the Peptidic Backbone of Glycopeptide Antibiotics

2004 ◽  
Vol 186 (18) ◽  
pp. 6093-6100 ◽  
Author(s):  
Oliver Puk ◽  
Daniel Bischoff ◽  
Claudia Kittel ◽  
Stefan Pelzer ◽  
Stefan Weist ◽  
...  
Keyword(s):  
Amino Acid ◽  
Building Blocks ◽  
Mass Spectrometry Analysis ◽  
Ionization Mass ◽  
Glycopeptide Antibiotics ◽  
P450 Monooxygenase ◽  
Spectrometry Analysis ◽  
Formation Pathway ◽  
Time Point

ABSTRACT The role of the putative P450 monooxygenase OxyD and the chlorination time point in the biosynthesis of the glycopeptide antibiotic balhimycin produced by Amycolatopsis balhimycina were analyzed. The oxyD gene is located directly downstream of the bhp (perhydrolase) and bpsD (nonribosomal peptide synthetase D) genes, which are involved in the synthesis of the balhimycin building block β-hydroxytyrosine (β-HT). Reverse transcriptase experiments revealed that bhp, bpsD, and oxyD form an operon. oxyD was inactivated by an in-frame deletion, and the resulting mutant was unable to produce an active compound. Balhimycin production could be restored (i) by complementation with an oxyD gene, (ii) in cross-feeding studies using A. balhimycina JR1 (a null mutant with a block in the biosynthesis pathway of the building blocks hydroxy- and dihydroxyphenylglycine) as an excretor of the missing precursor, and (iii) by supplementation of β-HT in the growth medium. These data demonstrated an essential role of OxyD in the formation pathway of this amino acid. Liquid chromatography-electrospray ionization-mass spectrometry analysis indicated the biosynthesis of completely chlorinated balhimycin by the oxyD mutant when culture filtrates were supplemented with nonchlorinated β-HT. In contrast, supplementation with 3-chloro-β-HT did not restore balhimycin production. These results indicated that the chlorination time point was later than the stage of free β-HT, most likely during heptapeptide synthesis.

scholarly journals Microdomain protein Nce102 is a local sensor of plasma membrane sphingolipid balance

2021 ◽  
Author(s):  
Jakub Zahumensky ◽  
Caroline Mota Fernandes ◽  
Petra Vesela ◽  
Maurizio Del Poeta ◽  
James Bernard Konopka ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Physiological Role ◽  
Building Blocks ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis ◽  
Signalling Molecules ◽  
Human Fungal Pathogen ◽  
Sphingolipid Biosynthesis ◽  
Complex Sphingolipids

Sphingolipids are essential building blocks of eukaryotic membranes and important signalling molecules, tightly regulated in response to environmental and physiological inputs. Mechanism of sphingolipid level perception at the plasma membrane remains unclear. In Saccharomyces cerevisiae, Nce102 protein has been proposed to function as sphingolipid sensor as it changes its plasma membrane distribution in response to sphingolipid biosynthesis inhibition. We show that Nce102 redistributes specifically in regions of increased sphingolipid demand, e.g., membranes of nascent buds. Furthermore, we report that production of Nce102 increases following sphingolipid biosynthesis inhibition and Nce102 is internalized when excess sphingolipid precursors are supplied. This suggests that the total amount of Nce102 in the plasma membrane is a measure of the current need for sphingolipids, whereas its local distribution marks sites of high sphingolipid demand. Physiological role of Nce102 in regulation of sphingolipid synthesis is demonstrated by mass spectrometry analysis showing reduced levels of complex sphingolipids and long-chain bases in nce102? deletion mutant. Nce102 behaves analogously in human fungal pathogen Candida albicans, suggesting a conserved principle of local sphingolipid control across species.

scholarly journals Structural Characterization of Act c 10.0101 and Pun g 1.0101—Allergens from the Non-Specific Lipid Transfer Protein Family

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 256
Author(s):  
Andrea O’Malley ◽  
Swanandi Pote ◽  
Ivana Giangrieco ◽  
Lisa Tuppo ◽  
Anna Gawlicka-Chruszcz ◽  
...  
Keyword(s):  
Immunoglobulin E ◽  
Lipid Transfer Protein ◽  
Mass Spectrometry Analysis ◽  
Lipid Transfer ◽  
Helical Structures ◽  
Spectrometry Analysis ◽  
X Ray Crystallography ◽  
Transfer Protein ◽  
Specific Lipid

(1) Background: Non-specific lipid transfer proteins (nsLTPs), which belong to the prolamin superfamily, are potent allergens. While the biological role of LTPs is still not well understood, it is known that these proteins bind lipids. Allergen nsLTPs are characterized by significant stability and resistance to digestion. (2) Methods: nsLTPs from gold kiwifruit (Act c 10.0101) and pomegranate (Pun g 1.0101) were isolated from their natural sources and structurally characterized using X-ray crystallography (3) Results: Both proteins crystallized and their crystal structures were determined. The proteins have a very similar overall fold with characteristic compact, mainly α-helical structures. The C-terminal sequence of Act c 10.0101 was updated based on our structural and mass spectrometry analysis. Information on proteins’ sequences and structures was used to estimate the risk of cross-reactive reactions between Act c 10.0101 or Pun g 1.0101 and other allergens from this family of proteins. (4) Conclusions: Structural studies indicate a conformational flexibility of allergens from the nsLTP family and suggest that immunoglobulin E binding to some surface regions of these allergens may depend on ligand binding. Both Act c 10.0101 and Pun g 1.0101 are likely to be involved in cross-reactive reactions involving other proteins from the nsLTP family.

Dereplication of Bromotyrosine-derived Metabolites by LC-PDA-MS and Analysis of the Chemical Profile of 14 Aplysina Sponge Specimens from the Brazilian Coastline

2010 ◽  
Vol 63 (6) ◽  
pp. 886 ◽  
Author(s):  
Michelli M. Silva ◽  
Juliana Bergamasco ◽  
Simone P. Lira ◽  
Norberto P. Lopes ◽  
Eduardo Hajdu ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Electrospray Ionization ◽  
Electrospray Ionization Mass Spectrometry ◽  
Marine Sponges ◽  
Mass Spectrometry Analysis ◽  
Ionization Mass ◽  
Chemical Profile ◽  
Spectrometry Analysis ◽  
Ion Clusters ◽  
Single Compound

In order to investigate the chemical profile of 14 specimens of Aplysina spp. marine sponges, we have developed a method based on LC-PDA-MS for the detection of bromotyrosine-derived metabolites. The method enabled the dereplication of three distinct chemotypes of bromotyrosine-derived compounds based on UV absorptions, which were further refined by electrospray ionization-mass spectrometry analysis of the brominated quasi-molecular ion clusters. This procedure led to either a single compound assignment, or a maximum of two possible isobaric compounds. The dereplication study indicated that the chemical profile of the 14 specimens of Aplysina spp. analyzed presented practically the same dibromotyrosine-derived compounds. The results obtained suggested a possible biogenetic pathway for the formation of dibromotyrosine-derived compounds of wide occurrence in Verongida sponges.

The amino acid sequence of porcine intestinal calcium-binding protein

1979 ◽  
Vol 57 (6) ◽  
pp. 737-748 ◽  
Author(s):  
Theo Hofmann ◽  
Michiko Kawakami ◽  
Anthony J. W. Hitchman ◽  
Joan E. Harrison ◽  
Keith J. Dorrington
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Intestinal Mucosa ◽  
Calcium Binding ◽  
Binding Protein ◽  
Troponin C ◽  
Calcium Binding Protein ◽  
Mass Spectrometry Analysis ◽  
Spectrometry Analysis

The complete amino acid sequence of the calcium-binding protein (CaBP) from pig intestinal mucosa has been determined: Ac-Ser-Ala-Gln-Lys-Ser-Pro-Ala-Glu-Leu-Lys-Ser-Ile-Phe-Glu-Lys-Tyr-Ala-Ala-Lys-Glu-Gly-Asp-Pro-Asn-Gln-Leu-Ser-Lys-Glu-Glu-Leu-Lys-Gln-Leu-Ile-Gln-Ala-Glu-Phe-Pro-Ser-Leu-Leu-Lys-Gly-Pro-Arg-Thr-Leu-Asp-Asp-Leu-Phe-Gln-Glu-Leu-Asp-Lys-Asn-Gly-Asn-Gly-Glu-Val-Ser-Phe-Glu-Glu-Phe-Gln-Val-Leu-Val-Lys-Lys-Ile-Ser-Gln-OH. The N-terminal octapeptide sequence was determined by mass spectrometry analysis by Morris and Dell. The first 45 residues of bovine CaBP differ only in six positions from the corresponding sequence of the porcine protein, except that the sequence starts in position two of the porcine sequence. The mammalian intestinal CaBP's belong to the troponin-C superfamily on the basis of an analysis by Barker and Dayhoff.

scholarly journals Characterization of anthocyanin from red sorghum (Sorghum bicolor) bran by liquid chromatography-electron spray ionization mass spectrometry analysis

2021 ◽  
pp. 146906672110357
Author(s):  
P Suganyadevi ◽  
M Saravanakumar ◽  
S Mohandas
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Sorghum Bicolor ◽  
Mass Spectrometry Analysis ◽  
Ionization Mass Spectrometry ◽  
Published Data ◽  
Ionization Mass ◽  
Spectrometric Data ◽  
Spectrometry Analysis ◽  
Sorghum Bran

In the present study, anthocyanin pigments from red sorghum ( Sorghum bicolor) bran were identified and characterized by Liquid Chromatography-Electron Spray Ionization Mass Spectrometry. The individual anthocyanins were identified by comparing their mass spectrometric data and retention times, published data. 3-deoxyanthocyanidins and methyl 3-deoxyanthocyanidins were identified in red sorghum bran. This paper presents complete LCMS profile and MS spectrometric data of red sorghum bran.

scholarly journals Selective Capture and Identification of Methicillin-Resistant Staphylococcus aureus by Combining Aptamer-Modified Magnetic Nanoparticles and Mass Spectrometry

2021 ◽  
Vol 22 (12) ◽  
pp. 6571
Author(s):  
Yu-Chen Liu ◽  
Katragunta Kumar ◽  
Cheng-Hsiu Wu ◽  
Kai-Chih Chang ◽  
Cheng-Kang Chiang ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Staphylococcus Aureus ◽  
Magnetic Nanoparticles ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Capture Rate ◽  
Mass Spectrometry Analysis ◽  
Ionization Mass ◽  
Methicillin Resistant ◽  
Spectrometry Analysis ◽  
Modified Magnetic Nanoparticles

A nucleic acid aptamer that specifically recognizes methicillin-resistant Staphylococcus aureus (MRSA) has been immobilized on magnetic nanoparticles to capture the target bacteria prior to mass spectrometry analysis. After the MRSA species were captured, they were further eluted from the nanoparticles and identified using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). The combination of aptamer-based capture/enrichment and MS analysis of microorganisms took advantage of the selectivity of both techniques and should enhance the accuracy of MRSA identification. The capture and elution efficiencies for MRSA were optimized by examining factors such as incubation time, temperature, and elution solvents. The aptamer-modified magnetic nanoparticles showed a capture rate of more than 90% under the optimized condition, whereas the capture rates were less than 11% for non-target bacteria. The as-prepared nanoparticles exhibited only a 5% decrease in the capture rate and a 9% decrease in the elution rate after 10 successive cycles of utilization. Most importantly, the aptamer-modified nanoparticles revealed an excellent selectivity towards MRSA in bacterial mixtures. The capture of MRSA at a concentration of 102 CFU/mL remained at a good percentage of 82% even when the other two species were at 104 times higher concentration (106 CFU/mL). Further, the eluted MRSA bacteria were successfully identified using MALDI mass spectrometry.

scholarly journals The Olsenella Uli Induced Pneumonia: A Case Report

2021 ◽  
Author(s):  
Yufen Yan ◽  
Hong Li ◽  
Shuai Li ◽  
Shuhui Liu ◽  
Nan Jia ◽  
...  
Keyword(s):  
Therapeutic Strategy ◽  
Pulmonary Infection ◽  
Mass Spectrometry Analysis ◽  
Causative Role ◽  
Positive Bacterium ◽  
Spectrometry Analysis ◽  
First Case ◽  
Infection Treatment ◽  
Third Generation Cephalosporins

Abstract Olsenella uli is a Gram-positive bacterium common in the oral cavity or gastrointestinal tract. Here we reported a first case of human pneumonia caused by the Olsenella uli. The identification of Olsenella uli was based on micromorphology, sequence analysis and mass spectrometry analysis of the bacteria recovered from sputum. Ceftazidime，one of the third generation cephalosporins was used for the anti-infection treatment of the patient. CT results showed a significant improvement of the pulmonary lesion and pleural effusion and recovery from pulmonary infection after 10 days. The mechanism underlying Olsenella uli induced pneumonia is unclear, our report suggests a causative role of gingival bacteria in pathogenesis of pneumonia, and the intervention by Ceftazidime may offer a therapeutic strategy for Olsenella uli infection.

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