Five Surfactin Isomers Produced during Cheonggukjang Fermentation by Bacillus pumilus HY1 and Their Properties

The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce cheonggukjang. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1008.7, 1022.7, 1036.7, and 1050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The mixture of five surfactin isoforms of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 μg/μL of surfactin. This study is the first-time report of five surfactin isomers of Bacillus pumilus strain HY1 during Korean soybean sauce cheonggukjang fermentation, which has cytotoxic properties.

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Anticancer Effect of the Five Surfactin Isomers Produced During Cheonggukjang Fermentation by Bacillus Pumilus HY1 Isolated From Korean Traditional Fermented Soy Sauce

10.20944/preprints202004.0072.v1 ◽

2020 ◽

Author(s):

Su Young Hong ◽

Dong Hee Lee ◽

Jin Hwan Lee ◽

Kye Man Cho

Keyword(s):

Mass Spectrometry ◽

Bacillus Pumilus ◽

Soy Sauce ◽

Ionization Time ◽

Esi Ms ◽

Anticancer Properties ◽

Chemical Structures ◽

Cyclic Lipopeptide ◽

Flight Mass Spectrometry ◽

Hydroxyl Fatty Acids

The cyclic lipopeptide produced from Bacillus pumilus strain HY1 was isolated from Korean soybean sauce. The chemical structures of the surfactin isomers were analyzed using matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). The five potential surfactin isoforms were detected with protonated masses of m/z 994.7, 1,008.7, 1022.7, 1036.7, and 1,050.7 and different structures in combination with Na+, K+, and Ca2+ ions. ESI-MS/MS analysis revealed that the isolated surfactin possessed the precise amino acid sequence LLVDLL and hydroxyl fatty acids with 12 to 16 carbons. The surfactin content during cheonggukjang fermentation increased from 0.3 to 51.2 mg/kg over 60 h of fermentation. The surfactin extraction of cheonggukjang inhibited the growth of two cancer cell lines. The growth of both MCF-7 and Caco-2 cells was strongly inhibited with 100 μg/μL surfactin. These results suggest that surfactins produced from strain HY1 have anticancer properties.

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Broad-Range PCR Coupled with Electrospray Ionization Time of Flight Mass Spectrometry for Detection of Bacteremia and Fungemia in Patients with Neutropenic Fever

Journal of Clinical Microbiology ◽

10.1128/jcm.01066-16 ◽

2016 ◽

Vol 54 (10) ◽

pp. 2513-2520 ◽

Cited By ~ 16

Author(s):

S. Desmet ◽

J. Maertens ◽

K. Bueselinck ◽

K. Lagrou

Keyword(s):

Mass Spectrometry ◽

Electrospray Ionization ◽

Time Of Flight ◽

Lower Sensitivity ◽

Consecutive Series ◽

Ionization Time ◽

Content Type ◽

Esi Ms ◽

Flight Mass Spectrometry ◽

Normal White Blood Cell

Infection is an important complication in patients with hematologic malignancies or solid tumors undergoing intensive cytotoxic chemotherapy. In only 20 to 30% of the febrile neutropenic episodes, an infectious agent is detected by conventional cultures. In this prospective study, the performance of broad-range PCR coupled with electrospray ionization time of flight mass spectrometry (PCR/ESI-MS) technology was compared to conventional blood cultures (BC) in a consecutive series of samples from high-risk hematology patients. In 74 patients, BC and a whole-blood sample for PCR/ESI-MS (Iridica BAC BSI; Abbott, Carlsbad, CA, USA) were collected at the start of each febrile neutropenic episode and, in case of persistent fever, also at day 5. During 100 different febrile episodes, 105 blood samples were collected and analyzed by PCR/ESI-MS. There was evidence of a bloodstream infection (BSI) in 36/105 cases (34%), based on 14 cases with both PCR/ESI-MS and BC positivity, 17 cases with BC positivity only, and 5 cases with PCR/ESI-MS positivity only. The sensitivity of PCR/ESI-MS was 45%, specificity was 93%, and the negative predictive value was 80% compared to blood culture. PCR/ESI-MS detected definite pathogens (Fusobacterium nucleatumandStreptococcus pneumoniae) missed by BC, whereas it missed both Gram-negative and Gram-positive organisms detected by BC. PCR/ESI-MS testing detected additional microorganisms but showed a low sensitivity (45%) compared to BC in neutropenic patients. Our results indicate a lower concordance between BC and PCR/ESI-MS in the neutropenic population than what has been previously reported in other patient groups with normal white blood cell distribution, and a lower sensitivity than other PCR-based methods.

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Exploring the Inhibition of CTX-M-9 by β-Lactamase Inhibitors and Carbapenems

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00089-11 ◽

2011 ◽

Vol 55 (7) ◽

pp. 3465-3475 ◽

Cited By ~ 25

Author(s):

Christopher R. Bethel ◽

Magdalena Taracila ◽

Teresa Shyr ◽

Jodi M. Thomson ◽

Anne M. Distler ◽

...

Keyword(s):

Mass Spectrometry ◽

Active Site ◽

Positive Charge ◽

Evolutionary Strategy ◽

Ionization Mass ◽

Ionization Time ◽

Esi Ms ◽

Flight Mass Spectrometry ◽

Before And After ◽

Enzyme Intermediate

ABSTRACTCurrently, CTX-M β-lactamases are among the most prevalent and most heterogeneous extended-spectrum β-lactamases (ESBLs). In general, CTX-M enzymes are susceptible to inhibition by β-lactamase inhibitors. However, it is unknown if the pathway to inhibition by β-lactamase inhibitors for CTX-M ESBLs is similar to TEM and SHV β-lactamases and why bacteria possessing only CTX-M ESBLs are so susceptible to carbapenems. Here, we have performed a kinetic analysis and timed electrospray ionization mass spectrometry (ESI-MS) studies to reveal the intermediates of inhibition of CTX-M-9, an ESBL representative of this family of enzymes. CTX-M-9 β-lactamase was inactivated by sulbactam, tazobactam, clavulanate, meropenem, doripenem, ertapenem, and a 6-methylidene penem, penem 1.Kivalues ranged from 1.6 ± 0.3 μM (mean ± standard error) for tazobactam to 0.02 ± 0.01 μM for penem 1. Before and after tryptic digestion of the CTX-M-9 β-lactamase apo-enzyme and CTX-M-9 inactivation by inhibitors (meropenem, clavulanate, sulbactam, tazobactam, and penem 1), ESI-MS and matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) identified different adducts attached to the peptide containing the active site Ser70 (+52, 70, 88, and 156 ± 3 atomic mass units). This study shows that a multistep inhibition pathway results from modification or fragmentation with clavulanate, sulbactam, and tazobactam, while a single acyl enzyme intermediate is detected when meropenem and penem 1 inactivate CTX-M-9 β-lactamase. More generally, we propose that Arg276 in CTX-M-9 plays an essential role in the recognition of the C3carboxylate of inhibitors and that the localization of this positive charge to a “region of the active site” rather than a specific residue represents an important evolutionary strategy used by β-lactamases.

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Tazobactam Inactivation of SHV-1 and the Inhibitor-resistant Ser130→ Gly SHV-1 β-Lactamase

Journal of Biological Chemistry ◽

10.1074/jbc.m311669200 ◽

2004 ◽

Vol 279 (19) ◽

pp. 19494-19501 ◽

Cited By ~ 19

Author(s):

Doritza Pagan-Rodriguez ◽

Xiang Zhou ◽

Reiko Simmons ◽

Christopher R. Bethel ◽

Andrea M. Hujer ◽

...

Keyword(s):

Mass Spectrometry ◽

Amino Acid Position ◽

Enzyme Inactivation ◽

Structural Basis ◽

Ionization Mass ◽

Resistant Variant ◽

Ionization Time ◽

Esi Ms ◽

Flight Mass Spectrometry ◽

Hospital Acquired

The increasing number of bacteria resistant to combinations of β-lactam and β-lactamase inhibitors is creating great difficulties in the treatment of serious hospital-acquired infections. Understanding the mechanisms and structural basis for the inactivation of these inhibitor-resistant β-lactamases provides a rationale for the design of novel compounds. In the present work, SHV-1 and the Ser130→ Gly inhibitor-resistant variant of SHV-1 β-lactamase were inactivated with tazobactam, a potent class A β-lactamase inhibitor. Apoenzymes and inhibited β-lactamases were analyzed by liquid chromatography-electrospray ionization mass spectrometry (LC-ESI/MS), digested with trypsin, and the products resolved using LC-ESI/MS and matrix-assisted laser desorption ionization-time of flight mass spectrometry. The mass increases observed for SHV-1 and Ser130→ Gly (+ Δ 88 Da and + Δ 70 Da, respectively) suggest that fragmentation of tazobactam readily occurs in the inhibitor-resistant variant to yield an inactive β-lactamase. These two mass increments are consistent with the formation of an aldehyde (+ Δ 70 Da) and a hydrated aldehyde (+ Δ 88 Da) as stable products of inhibition. Our results reveal that the Ser → Gly substitution at amino acid position 130 is not essential for enzyme inactivation. By examining the inhibitor-resistant Ser130→ Gly β-lactamase, our data are the first to show that tazobactam undergoes fragmentation while still attached to the active site Ser70in this enzyme. After acylation of tazobactam by Ser130→ Gly, inactivation proceeds independent of any additional covalent interactions.

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Methane ice photochemistry and kinetic study using laser desorption time-of-flight mass spectrometry at 20 K

Physical Chemistry Chemical Physics ◽

10.1039/c5cp00578g ◽

2015 ◽

Vol 17 (26) ◽

pp. 17346-17354 ◽

Cited By ~ 21

Author(s):

J.-B. Bossa ◽

D. M. Paardekooper ◽

K. Isokoski ◽

H. Linnartz

Keyword(s):

Mass Spectrometry ◽

Kinetic Study ◽

Time Of Flight ◽

Laser Desorption ◽

Effective Rate ◽

Branching Ratios ◽

Ionization Time ◽

Flight Mass Spectrometry ◽

Pure Methane ◽

First Time

Laser Desorption Post-Ionization Time-Of-Flight Mass Spectrometry is used to perform a systematic kinetic study on the pure methane photolysis in the condensed phase at 20 K and provides for the first time effective rate constants and branching ratios for primary processes leading to CH3, CH2, and CH radicals upon irradiation by VUV light in the 120–170 nm domain.

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