scholarly journals Occurrence of Pseudovitamin B12 and Its Possible Function as the Cofactor of Cobalamin-Dependent Methionine Synthase in a Cyanobacterium Synechocystis sp. PCC6803

2009 ◽  
Vol 55 (6) ◽  
pp. 518-521 ◽  
Author(s):  
Yuri TANIOKA ◽  
Yukinori YABUTA ◽  
Ryoichi YAMAJI ◽  
Shigeru SHIGEOKA ◽  
Yoshihisa NAKANO ◽  
...  
Keyword(s):  
Methionine Synthase ◽  
Pseudovitamin B12 ◽  
Synechocystis Sp

scholarly journals Biological Activity of Pseudovitamin B12 on Cobalamin-Dependent Methylmalonyl-CoA Mutase and Methionine Synthase in Mammalian Cultured COS-7 Cells

Molecules ◽  
2020 ◽  
Vol 25 (14) ◽  
pp. 3268 ◽  
Author(s):  
Tomohiro Bito ◽  
Mariko Bito ◽  
Tomomi Hirooka ◽  
Naho Okamoto ◽  
Naoki Harada ◽  
...  
Keyword(s):  
Biological Activity ◽  
Vitamin B12 ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Enzymatic Reaction ◽  
Intestinal Bacteria ◽  
Methionine Synthase ◽  
Trace Concentration ◽  
Pseudovitamin B12 ◽  
Transcobalamin Ii

Adenyl cobamide (commonly known as pseudovitamin B12) is synthesized by intestinal bacteria or ingested from edible cyanobacteria. The effect of pseudovitamin B12 on the activities of cobalamin-dependent enzymes in mammalian cells has not been studied well. This study was conducted to investigate the effects of pseudovitamin B12 on the activities of the mammalian vitamin B12-dependent enzymes methionine synthase and methylmalonyl-CoA mutase in cultured mammalian COS-7 cells to determine whether pseudovitamin B12 functions as an inhibitor or a cofactor of these enzymes. Although the hydoroxo form of pseudovitamin B12 functions as a coenzyme for methionine synthase in cultured cells, pseudovitamin B12 does not activate the translation of methionine synthase, unlike the hydroxo form of vitamin B12 does. In the second enzymatic reaction, the adenosyl form of pseudovitamin B12 did not function as a coenzyme or an inhibitor of methylmalonyl-CoA mutase. Experiments on the cellular uptake were conducted with human transcobalamin II and suggested that treatment with a substantial amount of pseudovitamin B12 might inhibit transcobalamin II-mediated absorption of a physiological trace concentration of vitamin B12 present in the medium.

Exemplar Abstract for Synechocystis sp. McNeill et al. 2006.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Synechocystis Sp

Exemplar Abstract for Synechocystis sp. McNeill et al. 2006.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Synechocystis Sp

Exemplar Abstract for Synechocystis sp. McNeill et al. 2006.

2003 ◽  
Author(s):  
Charles Thomas Parker ◽  
Dorothea Taylor ◽  
George M Garrity
Keyword(s):  
Synechocystis Sp

Stability and Folding of the Unusually Stable Hemoglobin from Synechocystis is Subtly Optimized and Dependent on the Key Heme Pocket Residues.

2020 ◽  
Vol 27 ◽  
Author(s):  
Sheetal Uppal ◽  
Mohd. Asim Khan ◽  
Suman Kundu
Keyword(s):  
Molten Globule ◽  
Life Forms ◽  
Model System ◽  
Heme Pocket ◽  
The Past ◽  
Specific Manner ◽  
Delivery Vehicles ◽  
The Stability ◽  
Key Residues ◽  
Synechocystis Sp

Aims: The aim of our study is to understand the biophysical traits that govern the stability and folding of Synechocystis hemoglobin, a unique cyanobacterial globin that displays unusual traits not observed in any of the other globins discovered so far. Background: For the past few decades, classical hemoglobins such as vertebrate hemoglobin and myoglobin have been extensively studied to unravel the stability and folding mechanisms of hemoglobins. However, the expanding wealth of hemoglobins identified in all life forms with novel properties, like heme coordination chemistry and globin fold, have added complexity and challenges to the understanding of hemoglobin stability, which has not been adequately addressed. Here, we explored the unique truncated and hexacoordinate hemoglobin from the freshwater cyanobacterium Synechocystis sp. PCC 6803 known as “Synechocystis hemoglobin (SynHb)”. The “three histidines” linkages to heme are novel to this cyanobacterial hemoglobin. Objective: Mutational studies were employed to decipher the residues within the heme pocket that dictate the stability and folding of SynHb. Methods: Site-directed mutants of SynHb were generated and analyzed using a repertoire of spectroscopic and calorimetric tools. Result: The results revealed that the heme was stably associated to the protein under all denaturing conditions with His117 playing the anchoring role. The studies also highlighted the possibility of existence of a “molten globule” like intermediate at acidic pH in this exceptionally thermostable globin. His117 and other key residues in the heme pocket play an indispensable role in imparting significant polypeptide stability. Conclusion: Synechocystis hemoglobin presents an important model system for investigations of protein folding and stability in general. The heme pocket residues influenced the folding and stability of SynHb in a very subtle and specific manner and may have been optimized to make this Hb the most stable known as of date. Other: The knowledge gained hereby about the influence of heme pocket amino acid side chains on stability and expression is currently being utilized to improve the stability of recombinant human Hbs for efficient use as oxygen delivery vehicles.

scholarly journals Enhanced Production of Photosynthetic Pigments and Various Metabolites and Lipids in the Cyanobacteria Synechocystis sp. PCC 7338 Culture in the Presence of Exogenous Glucose

Biomolecules ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 214
Author(s):  
YuJin Noh ◽  
Hwanhui Lee ◽  
Myeongsun Kim ◽  
Seong-Joo Hong ◽  
Hookeun Lee ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Cell Growth ◽  
Photosynthetic Pigments ◽  
Industrial Applications ◽  
Gas Chromatography Mass Spectrometry ◽  
Enhanced Production ◽  
Exogenous Glucose ◽  
Nanoelectrospray Ionization ◽  
Lipid Species ◽  
Synechocystis Sp

Synechocystis strains are cyanobacteria that can produce useful biomaterials for biofuel and pharmaceutical resources. In this study, the effects of exogenous glucose (5-mM) on cell growth, photosynthetic pigments, metabolites, and lipids in Synechocystis sp. PCC 7338 (referred to as Synechocystis 7338) were investigated. Exogenous glucose increased cell growth on days 9 and 18. The highest production (mg/L) of chlorophyll a (34.66), phycocyanin (84.94), allophycocyanin (34.28), and phycoerythrin (6.90) was observed on day 18 in Synechocystis 7338 culture under 5-mM glucose. Alterations in metabolic and lipidomic profiles under 5-mM glucose were investigated using gas chromatography-mass spectrometry (MS) and nanoelectrospray ionization-MS. The highest production (relative intensity/L) of aspartic acid, glutamic acid, glycerol-3-phosphate, linolenic acid, monogalactosyldiacylglycerol (MGDG) 16:0/18:1, MGDG 16:0/20:2, MGDG 18:1/18:2, neophytadiene, oleic acid, phosphatidylglycerol (PG) 16:0/16:0, and PG 16:0/17:2 was achieved on day 9. The highest production of pyroglutamic acid and sucrose was observed on day 18. We suggest that the addition of exogenous glucose to Synechocystis 7338 culture could be an efficient strategy for improving growth of cells and production of photosynthetic pigments, metabolites, and intact lipid species for industrial applications.

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