Process for preparing hyperpolarized substrates and method for MRI
申请人:Aime Silvio
公开号:US09694090B2
公开(公告)日:2017-07-04
The present invention generally relates to a process for the preparation of aqueous solutions of hyperpolarized molecules ready for use in in-vivo MR diagnostic imaging, the use thereof as MRI contrast agent in investigation methods for producing diagnostic MR images of a human or non-human animal body organ, region or tissue.
Kinetic and Structural Analysis of Two Linkers in the Tautomerase Superfamily: Analysis and Implications
作者:Bert-Jan Baas、Brenda P. Medellin、Jake A. LeVieux、Kaci Erwin、Emily B. Lancaster、William H. Johnson、Tamer S. Kaoud、R. Yvette Moreno、Marieke de Ruijter、Patricia C. Babbitt、Yan Jessie Zhang、Christian P. Whitman
DOI:10.1021/acs.biochem.1c00220
日期:2021.6.8
The tautomerase superfamily (TSF) is a collection of enzymes and proteins that share a simple β–α–β structural scaffold. Most members are constructed from a single-core β–α–β motif or two consecutively fused β–α–β motifs in which the N-terminal proline (Pro-1) plays a key and unusual role as a catalytic residue. The cumulative evidence suggests that a gene fusion event took place in the evolution of the TSF followed by duplication (of the newly fused gene) to result in the diversification of activity that is seen today. Analysis of the sequence similarity network (SSN) for the TSF identified several linking proteins (“linkers”) whose similarity links subgroups of these contemporary proteins that might hold clues about structure–function relationship changes accompanying the emergence of new activities. A previously uncharacterized pair of linkers (designated N1 and N2) was identified in the SSN that connected the 4-oxalocrotonate tautomerase (4-OT) and cis-3-chloroacrylic acid dehalogenase (cis-CaaD) subgroups. N1, in the cis-CaaD subgroup, has the full complement of active site residues for cis-CaaD activity, whereas N2, in the 4-OT subgroup, lacks a key arginine (Arg-39) for canonical 4-OT activity. Kinetic characterization and nuclear magnetic resonance analysis show that N1 has activities observed for other characterized members of the cis-CaaD subgroup with varying degrees of efficiencies. N2 is a modest 4-OT but shows enhanced hydratase activity using allene and acetylene compounds, which might be due to the presence of Arg-8 along with Arg-11. Crystallographic analysis provides a structural context for these observations.
Electrochemical carboxylation coupled with nitrite reduction catalyzed by [Fe4S4(SPh)4]2- and [Mo2Fe6S8(SPh)9]3-
作者:Koji Tanaka、Ryuhei Wakita、Toshio Tanaka
DOI:10.1021/ja00189a009
日期:1989.3
of CO 2 -saturated CH 3 CN containing [Fe 4 S 4 (SPh) 4 ] 2− , NO 2 − , COCH 3 , and a dehydration agent at −1.25 V vs SCE catalytically produced not only N2 accompanied by a small amount of N2 O but also COCH 2 COO − with the mole ratio 1:7. N2 O 22− as a precursor of N2 O was confirmed in the reaction mixture. The reduction of NO 2 − catalyzed by the reduced species of [Fe 4 S 4 (SPh) 4 ] 2−
含 [Fe 4 S 4 (SPh) 4 ] 2- 、NO 2 - 、COCH 3 和脱水剂的 CO 2 饱和 CH 3 CN 在 -1.25 V vs SCE 下的控制电位电解不仅催化产生 N 2伴随着少量的 N 2 O 和 COCH 2 COO - 摩尔比为 1:7。在反应混合物中确认N 2 O 2 2- 作为N 2 O 的前体。[Fe 4 S 4 (SPh) 4 ] 2- 的还原物质催化NO 2 - 的还原,因此通过NO - 、N 2 O 2 2- 和N 2 O 进行,其中PhCOCH 3 发挥作用每个反应步骤中质子源的数量和所得的 PhCOCH 2 - 与 CO 2 反应得到 PhCOCH 2 COO -
Diisopropylethylamine/hexafluoroisopropanol-mediated ion-pairing ultra-high-performance liquid chromatography/mass spectrometry for phosphate and carboxylate metabolite analysis: utility for studying cellular metabolism
作者:Lili Guo、Andrew J. Worth、Clementina Mesaros、Nathaniel W. Snyder、Jerry D. Glickson、Ian A. Blair
DOI:10.1002/rcm.7667
日期:2016.8.30
acid-containing metabolites was developed. Diisopropylethylamine (DIPEA) was used as an IP reagent in combination with reversed-phase liquid chromatography (RP-LC) and a triple quadrupole mass spectrometer using selected reaction monitoring (SRM) and negative electrospray ionization (NESI). An additional reagent, hexafluoroisopropanol (HFIP), which has been previously used to improve sensitivity of nucleotide