Glutamate Biosynthesis in Anaerobic Bacteria. I. The Citrate Pathways of Glutamate Synthesis in Clostridium kluyveri*

Biochemistry ◽  
1966 ◽  
Vol 5 (4) ◽  
pp. 1113-1118 ◽  
Author(s):  
Joseph R. Stern ◽  
Gunta Bambers
Keyword(s):  
Anaerobic Bacteria ◽  
Clostridium Kluyveri ◽  
Glutamate Synthesis ◽  
Glutamate Biosynthesis

Poly-γ-glutamate synthesis during formation of nematocyst capsules in Hydra

2002 ◽  
Vol 115 (4) ◽  
pp. 745-751 ◽  
Author(s):  
Susanne Szczepanek ◽  
Mihai Cikala ◽  
Charles N. David
Keyword(s):  
Acridine Orange ◽  
Monovalent Cations ◽  
High Concentration ◽  
Dapi Staining ◽  
Capsule Formation ◽  
Tubule Lumen ◽  
The Matrix ◽  
Glutamate Synthesis ◽  
Glutamate Biosynthesis

Nematocysts are explosive organelles found in all Cnidaria. Explosion of nematocyst capsules is driven by the high pressure within the capsule formed by the high concentration of poly-γ-glutamate in the capsule matrix. Poly-γ-glutamate is a polyanion that binds cations tightly, including the fluorescent cationic dyes acridine orange and DAPI(4′,6-diamidino-2-phenylindole). We have used acridine orange and DAPI staining to localize poly-γ-glutamate within capsules and to follow the biosynthesis of poly-γ-glutamate during capsule formation. The results indicate that poly-γ-glutamate biosynthesis occurs late in capsule formation after invagination of the tubule and that it is accompanied by swelling of the capsule due to increasing osmotic pressure. The matrix in all four capsule types is homogeneously filled with poly-γ-glutamate. In vivo this poly-γ-glutamate is complexed with monovalent cations. In addition, poly-γ-glutamate is formed within the tubule lumen of stenoteles. We argue that this poly-γ-glutamate is required to drive the two-step explosion process in stenotele nematocysts.

scholarly journals Ultrastructure of the Obligately Anaerobic Bacteria Clostridium Kluyveri and Cl. Acetobutylicum

1973 ◽  
Vol 26 (3) ◽  
pp. 547 ◽  
Author(s):  
KY Cho ◽  
CH Doy
Keyword(s):  
Cell Wall ◽  
Anaerobic Bacteria ◽  
Total Thickness ◽  
Obligately Anaerobic ◽  
Number Of Layers ◽  
Clostridium Kluyveri

The morphology of Cl. kluyveri is compared with that of CI. acetobutylicum. The multilayered cell wall of both organisms differ in the number of layers and total thickness.

A phase Ib trial of CB-839 (telaglenastat) in combination with radiation therapy and temozolomide in patients with IDH-mutated diffuse astrocytoma and anaplastic astrocytoma (NCT03528642).

2019 ◽  
Vol 37 (15_suppl) ◽  
pp. TPS2075-TPS2075 ◽  
Author(s):  
Sani Haider Kizilbash ◽  
Samuel McBrayer ◽  
John Port ◽  
Joel M. Reid ◽  
Ian Lanza ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Radiation Therapy ◽  
Systemic Exposure ◽  
Maximum Tolerated Dose ◽  
Resonance Spectroscopy ◽  
Diffuse Astrocytoma ◽  
Grade Ii ◽  
Branched Chain ◽  
Glutamate Synthesis ◽  
Glutamate Biosynthesis

TPS2075 Background: IDH mutant astrocytomas express high levels of 2-hydroxyglutarate (2-HG), an oncogenic metabolite which drives gliomagenesis. Excess 2-HG inhibits branched chain amino acid transaminase, which catalyzes glutamate synthesis from branched chain amino acids. This defect causes these tumors to become more reliant on glutaminase for glutamate biosynthesis from glutamine. CB-839 (telaglenastat) is a novel glutaminase inhibitor which is well tolerated in humans. McBrayer et al have recently demonstrated that CB-839 further depletes intracellular glutamate and glutathione in IDH mutant glioma cells, and enhances RT (radiation therapy) efficacy in an orthotopic glioma model. Methods: NCI #10218 is a CTEP supported phase I clinical trial investigating the safety and tolerability of CB-839 when combined with RT/TMZ (temozolomide) in patients with previously untreated IDH mutant grade II/III astrocytoma. Patients with grade II and III astrocytomas will be treated with 50.4 and 59.4 Gy of RT, respectively, with standard doses of concurrent TMZ. CB-839 will also be administered orally concurrently with RT, with doses escalated in cohorts based on a standard 3+3 design. After defining the maximum tolerated dose (MTD) of CB-839, an expansion cohort will evaluate the pre- and post-CB-839 therapy metabolome of patients with IDH mutant astrocytoma. Enrollment to this cohort will require measurable disease and patients will additionally be treated with a 7 day run-in of CB-839 at MTD prior to RT. The effect of CB-839 on the metabolome will be studied in both plasma (LC/MS/MS) and tumor (magnetic resonance spectroscopy), along with PK to confirm adequacy of systemic exposure. Preliminary data on neurocognitive endpoints will also be acquired. NCI #10218 is currently activated for enrollment to cohort 1. Clinical trial information: NCT03528642.

Confirmation of unusual stereochemistry of glutamate biosynthesis in clostridium kluyveri

FEBS Letters ◽  
1968 ◽  
Vol 1 (1) ◽  
pp. 74-76 ◽  
Author(s):  
Kurt Jungermann ◽  
Rudolf K. Thauer ◽  
Joseph Wenning ◽  
Karl Decker
Keyword(s):  
Clostridium Kluyveri ◽  
Glutamate Biosynthesis

scholarly journals Re-Citrate Synthase from Clostridium kluyveri Is Phylogenetically Related to Homocitrate Synthase and Isopropylmalate Synthase Rather Than to Si-Citrate Synthase

2007 ◽  
Vol 189 (11) ◽  
pp. 4299-4304 ◽  
Author(s):  
Fuli Li ◽  
Christoph H. Hagemeier ◽  
Henning Seedorf ◽  
Gerhard Gottschalk ◽  
Rudolf K. Thauer
Keyword(s):  
Primary Structure ◽  
Coenzyme A ◽  
Citrate Synthase ◽  
Anaerobic Bacteria ◽  
Strictly Anaerobic ◽  
Acetyl Coenzyme A ◽  
Isopropylmalate Synthase ◽  
Cell Extracts ◽  
Homocitrate Synthase ◽  
Clostridium Kluyveri

ABSTRACT The synthesis of citrate from acetyl-coenzyme A and oxaloacetate is catalyzed in most organisms by a Si-citrate synthase, which is Si-face stereospecific with respect to C-2 of oxaloacetate. However, in Clostridium kluyveri and some other strictly anaerobic bacteria, the reaction is catalyzed by a Re-citrate synthase, whose primary structure has remained elusive. We report here that Re-citrate synthase from C. kluyveri is the product of a gene predicted to encode isopropylmalate synthase. C. kluyveri is also shown to contain a gene for Si-citrate synthase, which explains why cell extracts of the organism always exhibit some Si-citrate synthase activity.

Glutamate Biosynthesis in Lactococcus lactis subsp. lactis NCDO 2118

1998 ◽  
Vol 64 (7) ◽  
pp. 2485-2489 ◽  
Author(s):  
P. Lapujade ◽  
M. Cocaign-Bousquet ◽  
P. Loubiere
Keyword(s):  
Amino Acids ◽  
Growth Rate ◽  
Lactococcus Lactis ◽  
Anaerobic Bacteria ◽  
Glutamate Synthase ◽  
Lag Phase ◽  
Carboxylase Activity ◽  
Nitrogen Donor ◽  
Reference Medium ◽  
Glutamate Biosynthesis

ABSTRACT Unlike other lactic acid bacteria, Lactococcus lactissubsp. lactis NCDO 2118 was able to grow in a medium lacking glutamate and the amino acids of the glutamate family. Growth in such a medium proceeded after a lag phase of about 2 days and with a reduced growth rate (0.11 h−1) compared to that in the reference medium containing glutamate (0.16 h−1). The enzymatic studies showed that a phosphoenolpyruvate carboxylase activity was present, while the malic enzyme and the enzymes of the glyoxylic shunt were not detected. As in most anaerobic bacteria, no α-ketoglutarate dehydrogenase activity could be detected, and the citric acid cycle was restricted to a reductive pathway leading to succinate formation and an oxidative branch enabling the synthesis of α-ketoglutarate. The metabolic bottleneck responsible for the limited growth rate was located in this latter pathway. As regards the synthesis of glutamate from α-ketoglutarate, no glutamate dehydrogenase was detected. While the glutamate synthase-glutamine synthetase system was detected at a low level, high transaminase activity was measured. The conversion of α-ketoglutarate to glutamate by the transaminase, the reverse of the normal physiological direction, operated with different amino acids as nitrogen donor. All of the enzymes assayed were shown to be constitutive.

scholarly journals Two Pathways for Glutamate Biosynthesis in the Syntrophic Bacterium Syntrophus aciditrophicus

2015 ◽  
Vol 81 (24) ◽  
pp. 8434-8444 ◽  
Author(s):  
Marie Kim ◽  
Huynh M. Le ◽  
Xiulan Xie ◽  
Xueyang Feng ◽  
Yinjie J. Tang ◽  
...  
Keyword(s):  
Amino Acids ◽  
Citrate Synthase ◽  
Carbon Sources ◽  
Krebs Cycle ◽  
Content Type ◽  
Cell Extracts ◽  
Cyclohexane Carboxylate ◽  
Glutamate Synthesis ◽  
Glutamate Biosynthesis ◽  
Syntrophus Aciditrophicus

ABSTRACTThe anaerobic metabolism of crotonate, benzoate, and cyclohexane carboxylate bySyntrophus aciditrophicusgrown syntrophically withMethanospirillum hungateiprovides a model to study syntrophic cooperation. Recent studies revealed thatS. aciditrophicuscontainsRe-citrate synthase but lacks the commonSi-citrate synthase. To establish whether theRe-citrate synthase is involved in glutamate synthesis via the oxidative branch of the Krebs cycle, we have used [1-13C]acetate and [1-14C]acetate as well as [13C]bicarbonate as additional carbon sources during axenic growth ofS. aciditrophicuson crotonate. Our analyses showed that labeled carbons were detected in at least 14 amino acids, indicating the global utilization of acetate and bicarbonate. The labeling patterns of alanine and aspartate verified that pyruvate and oxaloacetate were synthesized by consecutive carboxylations of acetyl coenzyme A (acetyl-CoA). The isotopomer profile and13C nuclear magnetic resonance (NMR) spectroscopy of the obtained [13C]glutamate, as well as decarboxylation of [14C]glutamate, revealed that this amino acid was synthesized by two pathways. Unexpectedly, only the minor route usedRe-citrate synthase (30 to 40%), whereas the majority of glutamate was synthesized via the reductive carboxylation of succinate. This symmetrical intermediate could have been formed from two acetates via hydration of crotonyl-CoA to 4-hydroxybutyryl-CoA. 4-Hydroxybutyrate was detected in the medium ofS. aciditrophicuswhen grown on crotonate, but an active hydratase could not be measured in cell extracts, and the annotated 4-hydroxybutyryl-CoA dehydratase (SYN_02445) lacks key amino acids needed to catalyze the hydration of crotonyl-CoA. BesidesClostridium kluyveri, this study reveals the second example of a microbial species to employ two pathways for glutamate synthesis.

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