- Thermostable enzyme-immobilized magnetic responsive Ni-based metal-organic framework nanorods as recyclable biocatalysts for efficient biosynthesis of: S -adenosylmethionine
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A novel magnetic responsive Ni-based metal-organic framework material was developed to efficiently separate and immobilize thermal enzymes with high catalytic performance. Ni-based metal-organic framework nanorods (Fe3O4/Ni-BTC) with high magnetic responsiveness are prepared conveniently by a one-pot hydrothermal process. With the characterization, it was confirmed that Ni-based metal-organic framework nanocomposites were synthesized as nanorods mounted with magnetic Fe3O4 nanoparticles on the surface. Although Fe3O4/Ni-BTC showed a preference for histidine-tagged enhanced green fluorescent protein (His-eGFP), we found that a variety of forces played roles in enzyme immobilization, including affinity between Ni2+ and histidine tags, electrostatic attraction, hydrogen bonding and hydrophobic forces. After understanding the mechanism of the as-prepared nanocomposites, a new immobilization strategy for thermostable S-adenosylmethionine synthetase (SAMS) was further evaluated. As a result, SAMS from cell lysate achieved about 95% activity recovery in the biosynthesis of S-adenosylmethionine (SAM) under high temperature conditions (70 °C) with a simple mixing step. At the same time, the immobilized enzyme was more stable against temperature variation (by nearly 8-fold in an 80 °C water bath after 2 h) and extreme pH (by nearly 1.3-fold at pH 3) and exhibited excellent reusability after immobilization. This work indicates that magnetic responsive Ni-based nanorods are highly promising for thermostable enzyme immobilization with high efficiency and stability.
- He, Jie,Sun, Shanshan,Zhou, Zhao,Yuan, Qipeng,Liu, Yanhui,Liang, Hao
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supporting information
p. 2077 - 2085
(2019/02/12)
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- Mechanism of a Class C Radical S-Adenosyl- l -methionine Thiazole Methyl Transferase
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The past decade has seen the discovery of four different classes of radical S-adenosylmethionine (rSAM) methyltransferases that methylate unactivated carbon centers. Whereas the mechanism of class A is well understood, the molecular details of methylation by classes B-D are not. In this study, we present detailed mechanistic investigations of the class C rSAM methyltransferase TbtI involved in the biosynthesis of the potent thiopeptide antibiotic thiomuracin. TbtI C-methylates a Cys-derived thiazole during posttranslational maturation. Product analysis demonstrates that two SAM molecules are required for methylation and that one SAM (SAM1) is converted to 5′-deoxyadenosine and the second SAM (SAM2) is converted to S-adenosyl-l-homocysteine (SAH). Isotope labeling studies show that a hydrogen is transferred from the methyl group of SAM2 to the 5′-deoxyadenosine of SAM1 and the other two hydrogens of the methyl group of SAM2 appear in the methylated product. In addition, a hydrogen appears to be transferred from the β-position of the thiazole to the methyl group in the product. We also show that the methyl protons in the product can exchange with solvent. A mechanism consistent with these observations is presented that differs from other characterized radical SAM methyltransferases.
- Zhang, Zhengan,Mahanta, Nilkamal,Hudson, Graham A.,Mitchell, Douglas A.,Van Der Donk, Wilfred A.
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p. 18623 - 18631
(2017/12/26)
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- Facile chemoenzymatic strategies for the synthesis and utilization of S-adenosyl-L-methionine analogues
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A chemoenzymatic platform for the synthesis of S-adenosyl-L-methionine (SAM) analogues compatible with downstream SAM-utilizing enzymes is reported. Forty-four non-native S/Se-alkylated Met analogues were synthesized and applied to probing the substrate specificity of five diverse methionine adenosyltransferases (MATs). Human MAT II was among the most permissive of the MATs analyzed and enabled the chemoenzymatic synthesis of 29 non-native SAM analogues. As a proof of concept for the feasibility of natural product alkylrandomization , a small set of differentially-alkylated indolocarbazole analogues was generated by using a coupled hMAT2-RebM system (RebM is the sugar C4′-O-methyltransferase that is involved in rebeccamycin biosynthesis). The ability to couple SAM synthesis and utilization in a single vessel circumvents issues associated with the rapid decomposition of SAM analogues and thereby opens the door for the further interrogation of a wide range of SAM utilizing enzymes. Mix and MATch: Methionine adenosyltransferase (MAT) was used to synthesize S-adenosylmethionine (SAM) analogues in a method directly compatible with downstream SAM-utilizing enzymes. As a proof of concept for the feasibility of natural product alkylrandomization by using this method, a coupled strategy in which MAT was applied in conjunction with the methyltransferase RebM was used to generate a small set of indolocarbazole analogues.
- Singh, Shanteri,Zhang, Jianjun,Huber, Tyler D.,Sunkara, Manjula,Hurley, Katherine,Goff, Randal D.,Wang, Guojun,Zhang, Wen,Liu, Chunming,Rohr, Juergen,Van Lanen, Steven G.,Morris, Andrew J.,Thorson, Jon S.
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supporting information
p. 3965 - 3969
(2014/05/06)
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- Chemical Synthesis Of S-Adenosyl-L-Methionine With Enrichment Of (S,S)-Isomer
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This invention relates to an improved process for the industrial manufacture of S-adenosyl-L-methionine (SAMe) of formula (I), which consists of stereo-selective methylation of S-adenosyl-L-homocysteine (SAH) with the enrichment of active (S,S)-isomer.
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Page/Page column 3-4
(2008/06/13)
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- Combinations of tyrosine, methylating agents, phospholipids, fatty acids, and St. John's Wort for the treatment of mental disturbances
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This invention provides therapeutic compositions for the treatment or prevention of mental disturbances such as depressive states and for regulating the level of certain neurotransmitters and thereby improving the function of the central nervous system and cognitive function in humans and other animals. The therapeutic compositions comprise any two or more of tyrosine, one or more methylating agents, one or more phospholipids, one or more fatty acids and St. John's Wort (Hypericum perforatum), whether naturally, synthetically, or semi-synthetically derived. The invention also provides a method of administering these compositions to humans or animals in need thereof.
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