由于生物系统中仅含有微量氟,19 F MRI 对于体内成像很有价值。然而,由于 MRI 的灵敏度较低,设计新的含氟化合物仍然是获得足够19 F 信号的重大挑战。在这里,我们描述了一类新型高信号水溶性含氟化合物,即19 F MRI 成像剂。聚酰胺主链用于调节蛋白水解稳定性,以避免滞留在体内,这是当前最先进的全氟化学品的限制。我们发现,含有交替的 N-ε-三氟乙酰基赖氨酸和赖氨酸的非结构化肽可提供简并19 F NMR 信号。19 F MRI 模型图像在微摩尔浓度下提供了足够的对比度,显示出最终临床应用的前景。最后,当与大蛋白质缀合时,保留了简并的高信号特征,这表明其在体内靶向应用中的潜力,包括分子成像和细胞追踪。
Effects of Lysine Acetylation in a β-Hairpin Peptide: Comparison of an Amide−π and a Cation−π Interaction
摘要:
The acetylation of lysine is a common posttranslational modification of histone proteins, and the interaction of acetylated lysines with aromatic rings is commonly observed in transcriptionally relevant protein-protein interactions. To determine the nature of this interaction and its potential role in protein structure and function, the effect of lysine acetylation on its interaction with tryptophan has been investigated within the context of a beta-hairpin peptide. Acetylation of Lys results in the replacement of a cation-pi interaction with an amide-pi interaction. Despite the loss of positive charge, the interaction energy is not significantly perturbed, although the geometry of interaction is influenced such that the amide NH interacts directly with the Trp ring. Thermodynamic analysis indicates an enthalpic driving force for the stabilization, indicating a polar-pi interaction. Acyl lysine analogues formyl lysine and trifluoroacetyl lysine were used to further investigate the sterics and electronics of the interaction.
The present invention relates to a method of production of a hydrazide modified sugar comprising a step of reacting a sugar with a hydrazide in a reaction solvent at a pH of between 3 and 5.5, wherein the solvent comprises an aqueous based solvent and an optional polar organic co-solvent. A further aspect of the invention relates to a method of production of a polysaccharide epitope carrier protein conjugate comprising the steps of: (a) reacting a polysaccharide epitope with a hydrazide to form a hydrazide modified polysaccharide epitope; (b) reacting the hydrazide modified polysaccharide epitope with a linker that has been pre-coupled to a carrier protein. Another aspect of the invention relates to a method of production of a sugar-dihydrazide-aldehyde adduct comprising the steps of: (a) producing a hydrazide modified sugar using a method according to the invention, wherein the hydrazide modified sugar includes a further unreacted hydrazide moiety; and (b) reacting the further hydrazide moiety with the aldehyde functionality of a linker group.
[EN] REDOX DEHYDRATION COUPLING CATALYSTS AND METHODS RELATED THERETO<br/>[FR] CATALYSEURS DE COUPLAGE DE DÉSHYDRATATION RÉDOX ET PROCÉDÉS ASSOCIÉS À CEUX-CI
申请人:UNIV EMORY
公开号:WO2017070157A1
公开(公告)日:2017-04-27
This disclosure relates to synthetic coupling methods using catalytic molecules. In certain embodiments, the catalytic molecules comprise heterocyclic thiolamide, S-acylthiosalicylamide, disulfide, selenium containing heterocycle, diselenide compound, ditelluride compound or tellurium containing heterocycle. Catalytic molecules disclosed herein are useful as catalysts in the transformation of hydroxy group containing compounds to amides, esters, ketones, and other carbon to heteroatom or carbon to carbon transformations.
In this article, we have explored the chemical interactions of tyrosine-based asymmetric urea ligands in the binding pockets of prostate specific membrane antigen (PSMA) through in silico studies. The S1 pocket of the PSMA protein offers better scope for modifications in the urea ligands to improve the binding affinity. Accordingly, tyrosine-based (S)-2-(3-((S)-1-carboxy-2-(4-(carboxymethoxy)pheny
Selective Substrates and Activity-Based Probes for Imaging of the Human Constitutive 20S Proteasome in Cells and Blood Samples
作者:Wioletta Rut、Marcin Poręba、Paulina Kasperkiewicz、Scott J. Snipas、Marcin Drąg
DOI:10.1021/acs.jmedchem.8b00026
日期:2018.6.28
the HyCoSuL approach, we designed and synthesized novel and selective fluorogenic substrates for each of these three constitutive 20S proteasome activities and applied them to assess inhibition of proteasome subunits by MG-132 and a clinically used inhibitor bortezomib. Our results confirm the utility of designed substrates in biochemical assays. Furthermore, selective peptide sequences obtained in this
An Optimized Protocol for the Synthesis of Peptides Containing
<i>trans</i>
‐Cyclooctene and Bicyclononyne Dienophiles as Useful Multifunctional Bioorthogonal Probes
incorporation of certain functional groups into peptide sequences is restricted by the compatibility of the building blocks with conditions used during SPPS. In particular, the introduction of highly reactive groups used in modern bioorthogonal reactions into peptides remains elusive. Here, we present an optimized synthetic protocol enabling installation of two strained dienophiles, trans-cyclooctene