- Isomer-sensitive deboronation in reductive aminations of aryl boronic acids
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Deboronation is observed during the reductive amination of formylphenylboronic acid (FPBA) to the amine termini and side chains of peptides. This deboronation is sensitive to the isomerism of the boronic acid (BA), with ortho-FPBA yielding complete deboronation in the preparation of an N-terminally-modified dipeptide. The observed behavior is also clearly mediated by the chemical identity of the amine substrate. These results reveal a previously undocumented subtlety of BA functionalization and highlight the importance of thorough spectroscopic characterization in the preparation of peptide and small molecule BAs.
- Jones, Brad H.,Wheeler, David R.,Wheeler, Jill S.,Miller, Lance L.,Alam, Todd M.,Spoerke, Erik D.
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- Search for fibrous aggregates potentially useful in regenerative medicine formed under physiological conditions by self-assembling short peptides containing two identical aromatic amino acid residues
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This study investigates the propensity of short peptides to self-organize and the influence of aggregates on cell cultures. The dipeptides were derived from both enantiomers of identical aromatic amino acids and tripeptides were prepared from two identica
- Fraczyk, Justyna,Lipinski, Wojciech,Chaberska, Agata,Wasko, Joanna,Rozniakowski, Kamil,Kaminski, Zbigniew J.,Bogun, Maciej,Draczynski, Zbigniew,Menaszek, Elzbieta,Stodolak-Zych, Ewa,Kaminska, Marta,Kolesinska, Beata
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- L -Diphenylalanine microtubes as a potential drug-delivery system: Characterization, release kinetics, and cytotoxicity
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Microtubes obtained from the self-assembly of l-diphenylalanine (FF-MTs) were evaluated as potential vehicles for drug delivery. The biological marker Rhodamine B (RhB) was chosen as a model drug and conjugated to the peptide arrays during self-organization in the liquid phase. Microscopy and X-ray studies were performed to provide morphological and structural information. The data revealed that the cargo was distributed either in small aggregates at the hydrophobic surface of the FF-MTs or homogeneously embedded in the structure, presumably anchored at polar sites in the matrix. Raman spectroscopy revealed notable shifts of the characteristic RhB resonance peaks, demonstrating the successful conjugation of the fluorophore and peptide assemblies. In vitro assays were conducted in erythrocytes and fibroblast cells. Interestingly, FF-MTs were found to modulate the release of the load. The release of RhB from the FF-MTs followed first-order kinetics with a steady-state profile, demonstrating the potential of these carriers to deliver drugs at constant rates in the body. Cytotoxicity investigations revealed high cell viability up to concentrations of 5 mg mL-1, demonstrating the low toxicity of the FF-MTs.
- Silva, Rondes F.,Araújo, Daniele R.,Silva, Emerson R.,Ando, Ro?mulo A.,Alves, Wendel A.
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- Convenient solid-phase synthesis of oligopeptides using pentacoordinated phosphoranes with amino acid residue as building blocks
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The reactive intermediates of pentacoordinated phosphoranes with amino acids (P(5)-AA) as building blocks, which were obtained by the reaction of O-phenylene phosphorochloridate with N,O-bis(trimethylsilyl)amino acids, were linked to a solid-phase support containing a hydroxymethyl polystyrene functional group. The first amino acid residue was coupled to the solid-phase support after washing the resin with organic solvent. Repeating the procedure led to oligopeptides linked on the resin. A series of free oligopeptides including tetra-Gly, di-Val, tri-Val, di-Leu, di-Phe, and Phe-Leu were obtained after cleavage from solid-phase support. The structure of these oligopeptides were determined by IR, 1H NMR, FAB-MS, and HPLC.
- Li, Zhaolong,Fu, Hua,Gong, Hegui,Zhao, Yufen
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- A dynamic combinatorial library for biomimetic recognition of dipeptides in water
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Small peptides are involved in countless biological processes. Hence selective binding motifs for peptides can be powerful tools for labeling or inhibition. Finding those binding motifs, especially in water which competes for intermolecular H-bonds, poses an enormous challenge. A dynamic combinatorial library can be a powerful method to overcome this issue. We previously reported artificial receptors emerging form a dynamic combinatorial library of peptide building blocks. In this study we aimed to broaden this scope towards recognition of small peptides. Employing CXC peptide building blocks, we found that cyclic dimers of oxidized CFC bind to the aromatic peptides FF and YY (K ≈ 229-702 M-1), while AA binds significantly weaker (K ≈ 65-71 M-1).
- Klepel, Florian,Ravoo, Bart Jan
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supporting information
p. 1588 - 1595
(2020/09/16)
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- Tetrafluoroaryl azide as an N-Terminal capping group for click-To-dissolve diphenylalanine hydrogels
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The synthesis of a bioorthogonal-responsive low molecular weight diphenylalanine (PhePhe)-based hydrogel that is capped with a 4-Azido-2,3,5,6-Tetrafluorobenzyl carbamate self-immolative linker is reported. The hydrogelator (AzF4-PhePhe) generates a stable hydrogel at 0.1 wt%, and rapidly reacts with the bioorthogonal reagent trans-cyclooctene (TCO), inducing a gel-To-solution transition. The critical gel concentration is five-fold lower than our previously synthesized non-fluorinated hydrogelator (Az-PhePhe), and the minimum concentration of TCO required for visible gel-To-solution transition in 24 hours is 1 mM. Doxorubicin can be encapsulated in the hydrogel and TCO-Triggered dissolution results in 76% and 89% release after 10 and 24 hours, respectively. Compared with our non-substituted aryl azide capping group used for Az-PhePhe, the tetrafluorinated aryl azide group improves the stability of the hydrogel in unbuffered water at a lower critical gel concentration, while improving sensitivity towards the bioorthogonal reagent TCO.
- Dadhwal, Sumit,Fairhall, Jessica M.,Gamble, Allan B.,Hook, Sarah
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p. 9234 - 9244
(2020/03/19)
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- Synthesis of a functionalized dipeptide for targeted delivery and pH-sensitive release of chemotherapeutics
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Targeted delivery of chemotherapeutics to tumor cells is one of the biggest challenges in cancer treatment. Herein, we synthesized smart dipeptide nanoparticles for cancer-specific targeting and intracellular pH-sensitive release of chemotherapeutics. Diphenylalanine peptide was synthesized and further developed as nanoparticles (NPs), which were functionalized with folic acid utilizing the carbodiimide reaction. Doxorubicin (Dox) was loaded to self-assembled non-functionalized (FF-Dox) and folate functionalized peptides NPs (FA-FF-Dox). Moreover, the experiments revealed the pH-sensitive release of Dox for both FA-FF-Dox and FF-Dox due to the protonation of the Schiff base and the amines present in the peptides at low pH, enhancing intracellular release subsequent to receptor-mediated endocytosis. Further, biodistribution and the pharmacokinetics study revealed enhanced targeting efficiency of FA-FF-Dox with high accumulation in tumor cells.
- Kiran, Sonia,Dwivedi, Pankaj,Khatik, Renuka,Hameed, Sadaf,Dwivedi, Monika,Huang, Fangsheng,Xu, Ronald X.
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supporting information
p. 285 - 288
(2019/12/30)
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- Effect of high hydrostatic pressure on prebiotic peptide synthesis
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Prebiotic peptide synthesis is a central issue concerning life's origins. Many studies considered that life might come from Hadean deep-sea environment, that is, under high hydrostatic pressure conditions. However, the properties of prebiotic peptide formation under high hydrostatic pressure conditions have seldom been mentioned. Here we report that the yields of dipeptides increase with raised pressures. Significantly, effect of pressure on the formation of dipeptide was obvious at relatively low temperature. Considering that the deep sea is of high hydrostatic pressure, the pressure may serve as one of the key factors in prebiotic peptide synthesis in the Hadean deep-sea environment. The high hydrostatic pressure should be considered as one of the significant factors in studying the origin of life.
- Ying, Jianxi,Chen, Peng,Wu, Yile,Yang, Xu,Yan, Kaili,Xu, Pengxiang,Zhao, Yufen
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supporting information
p. 367 - 370
(2018/06/18)
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- A PROCESS FOR PREPARATION OF A PEPTIDE
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The present invention relates to a novel process for preparation of peptides having amino acid chain length in the range of 2-40 comprises the steps: i) attaching an end-blocked amino acid with an ionic liquid based solid support in presence of an ionic solvent to obtain an end-terminal blocked amino acid attached ionic liquid; ii) removing end-terminal blocking agent from the end-terminal blocked amino acid attached ionic liquid of step i) followed by work up to obtain an amino acid attached ionic liquid; iii) repeating steps i) through ii) one or more times to obtain a polypeptide attached ionic liquid; and iv) detaching the polypeptide from the polypeptide attached ionic liquid of step iii) to obtain the polypeptide. Said process does not use any auxiliary reagents like dehydrating agent or activating agent. The use of ionic liquids as supports as well as solvents result in the faster kinetics of the process, the separation issues are reduced, and the process has no racemization issues.
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Page/Page column 13-14; 15-16
(2018/07/29)
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- Methods for 20S Immunoproteasome and 20S Constitutive Proteasome Determination Based on SPRI Biosensors
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The 20S proteasome, released into the circulation, is a novel cancer biomarker. It exists in two forms: the constitutive proteasome (20Sc) and the immunoproteasome (20Si), which both have separate diagnostic significance. The aim of this work was to develop new methods for 20Si and 20Sc determination. Five alternative specific biosensors usable with the surface plasmon resonance imaging (SPRI) technique for 20Si determination have been developed. Specific 20Si entrapment on the biosensor surface from an analyzed solution was achieved by means of an immobilized specific 20Si receptor. Four of the biosensors contain newly synthesized specific 20Si receptors, while the fifth contains the inhibitor ONX 0914. A method for 20Sc determination using an SPRI biosensor containing PSI inhibitor has been developed. By the introduction of an inhibitor blocking 20Si, 20Sc is selectively determined. All of the methods developed for 20Si and 20Sc determination exhibit good selectivity and satisfactory precision, recoveries and dynamic response ranges. 20Si and 20Sc were determined in blood plasma samples from healthy donors and patients with acute leukemia. In the case of these patients 20Si was the major component, and its level was more than one order of magnitude higher than in the healthy donors.
- Anna, Sankiewicz,Agnieszka, Markowska,Zenon, Lukaszewski,Beata, Puzan,Ewa, Gorodkiewicz
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p. 174 - 185
(2017/03/22)
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- Redox-triggered changes in the self-assembly of a ferrocene-peptide conjugate
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Ultrasonication of a ferrocene conjugate of a short amyloid peptide (Aβ18-20) in toluene causes formation of an organogel, which undergoes dramatic structural changes upon oxidation from a nanofibrillar network to spherical micelles. This morphological change is redox-controlled and reversible. the Partner Organisations 2014.
- Adhikari, Bimalendu,Kraatz, Heinz-Bernhard
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p. 5551 - 5553
(2014/05/20)
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- Peptide-nanofiber-supported palladium nanoparticles as an efficient catalyst for the removal of N-terminus protecting groups
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Sonication-induced tryptophan- and tyrosine-based peptide bolaamphiphile nanofibers have been used to synthesize and stabilize Pd nanoparticles under physiological conditions. The peptide bolaamphiphile self-assembly process has been thoroughly studied by using several spectroscopic and microscopic techniques. The stiffness of the soft hydrogel matrix was measured by an oscillatory rheological experiment. FTIR and circular dichroism (CD) experiments revealed a hydrogen-bonded β-sheet conformation of peptide bolaamphiphile molecules in a gel-phase medium. The π-π stacking interactions also played a crucial role in the self-assembly process, which was confirmed by fluorescence spectroscopy. Electron (SEM and TEM) and atomic force microscopy (AFM) studies showed that the peptide bolaamphiphile molecules self-assemble into nanofibrillar structures. Pd nanoparticles were synthesized in the hydrogel matrix in which redox-active tryptophan and tyrosine residues reduce the metal ions to metal nanoparticles. The size of the Pd nanoparticles are in the range of 3-9 nm, and are stabilized by peptide nanofibers. The peptide-nanofiber- supported Pd nanoparticles have shown effective catalytic activity for the removal of N-terminus protecting groups of amino acids and peptides.
- Maity, Indrajit,Manna, Manoj K.,Rasale, Dnyaneshwar B.,Das, Apurba K.
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p. 413 - 420
(2014/04/03)
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- Biomimetic peptide bond formation in water with aminoacyl phosphate esters
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Aminoacyl phosphates, biomimetic analogues of aminoacyl adenylates, react efficiently with amino acid esters to form dipeptides with retention of stereochemical integrity. The reactions are selective and occur readily in the presence of nucleophiles other than amino groups on their side chains. Aminoacyl phosphate esters that lack an amino-protecting group are also suitable for peptide bond formation, leading to a simplified overall process.
- Dhiman, Raj S.,Opinska, Liliana Guevara,Kluger, Ronald
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supporting information; experimental part
p. 5645 - 5647
(2011/09/15)
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- Peptide bond formation by aminolysin-A catalysis: A simple approach to enzymatic synthesis of diverse short oligopeptides and biologically active puromycins
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A new S9 family aminopeptidase derived from the actinobacterial thermophile Acidothermus cellulolyticus was cloned and engineered into a transaminopeptidase by site-directed mutagenesis of catalytic Ser491 into Cys. The engineered biocatalyst, designated aminolysin-A, can catalyze the formation of peptide bonds to give linear homo-oligopeptides, hetero-dipeptides, and cyclic dipeptides using cost-effective substrates in a one-pot reaction. Aminolysin-A can recognize several C-terminal-modified amino acids, including the l- and d-forms, as acyl donors as well as free amines, including amino acids and puromycin aminonucleoside, as acyl acceptors. The absence of amino acid esters prevents the formation of peptides; therefore, the reaction mechanism involves aminolysis and not a reverse reaction of hydrolysis. The aminolysin system will be a beneficial tool for the preparation of structurally diverse peptide mimetics by a simple approach.
- Usuki, Hirokazu,Yamamoto, Yukihiro,Arima, Jiro,Iwabuchi, Masaki,Miyoshi, Shozo,Nitoda, Teruhiko,Hatanaka, Tadashi
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supporting information; experimental part
p. 2327 - 2335
(2011/05/02)
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- Engineered transaminopeptidase, aminolysin-S for catalysis of peptide bond formation to give linear and cyclic dipeptides by one-pot reaction
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Aminopeptidase from Streptomyces thermocyaneoviolaceus NBRC14271 was engineered into transaminopeptidase and used to catalyze an aminolysis reaction to give linear and cyclic dipeptides from cost-effective substrates such as the ester derivatives of amino
- Usuki, Hirokazu,Uesugi, Yoshiko,Arima, Jiro,Yamamoto, Yukihiro,Iwabuchi, Masaki,Hatanaka, Tadashi
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supporting information; experimental part
p. 580 - 582
(2010/05/01)
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- Discovery of dipeptides with high affinity to the specific binding site for substance P1-7
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Substance P 1-7 (SP1-7, H-Arg-Pro-Lys-Pro-Gln-Gln-Phe-OH) is the major bioactive metabolite of substance P. The interest in this heptapeptide originates from the observation that it modulates, and in certain cases opposes the effects of the parent peptide, e.g., the nociceptive effect. The μ-opioid receptor agonist endomorphin-2 (EM-2, H-Tyr-Pro-Phe-Phe-NH2) has been found to also interact with the specific binding site of SP 1-7 with only a 10-fold lower affinity compared to the native peptide. Considering the smaller size of EM-2 compared to the target heptapeptide, it was selected as a lead compound in the development of low-molecular-weight ligands to the SP1-7 binding site. An alanine scan and truncation study led to the unexpected discovery of the dipeptide H-Phe-Phe-NH2 (Ki = 1.5 nM), having equal affinity as the endogenous heptapeptide SP1-7. Moreover, the studies show that the C-terminal phenylalanine amide is crucial for the affinity of the dipeptide.
- Fransson, Rebecca,Botros, Milad,Sk?ld, Christian,Nyberg, Fred,Lindeberg, Gunnar,Hallberg, Mathias,Sandstr?m, Anja
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supporting information; experimental part
p. 2383 - 2389
(2010/08/22)
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- PhFl acetic acid: A new linker for solid phase organic synthesis
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A 9-phenylfluoren-9-yl based linker for the immobilization of nitrogen and oxygen nucleophiles is described. Improved acid stability compared to the common trityl linker is demonstrated by a quantitative method for analysis of loading. This new linker is used for the synthesis of a peptide alcohol in the 'inverse' direction via reduction of the corresponding N linked peptide methyl ester. Several other nucleophiles are immobilized and further modified. TFA treatment releases the corresponding products in high purity.
- Bleicher, Konrad H.,Wareing, James R.
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p. 4591 - 4594
(2007/10/03)
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- Application of 4-Polystyryltriphenylmethyl Chloride to the Syntheses of Peptides and Amino Acid Derivatives
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Use of polymer-bound trityl chloride as an α-amino protecting group of amino acids allows simple and high-yield syntheses of amino acid derivatives and peptides.
- Barlos, Kleomenis,Gatos, Dimitrios,Kallitsis, Ioannis,Papaioannou, Dionysios,Sotiriou, Petros
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p. 1079 - 1082
(2007/10/02)
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- Anchoring of Amino Acids on Hydroxy Group-Containing Resins and Their Application to Peptide Synthesis Using N-Tritylamino Acid 1-Benzotriazolyl Esters
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Trt- and Fmoc-amino acids has been attached to p-alkoxybenzylalcohol resin (ABAR, 1) and diphenylmethanol resin (DPMR, 2) using triphenylphosphan (TPP) and diethyl azodicarboxylate (DEAD) at 0 deg C in tetrahydrofuran.The derived resins have been applied in "solid-phase" peptide synthesis using N-tritylamino acid 1-benzotriazolyl esters 9.
- Barlos, Kleomenis,Gatos, Dimitrios,Kallitsis, John,Papaioannou, Dionysios,Sotiriou, Petros,Schaefer, Wolfram
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p. 1031 - 1036
(2007/10/02)
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- The Steric Hindrance of the Stepwise Reaction of N-Carboxy α-Amino Acid Anhydride with the α-Amino Acid Ester
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The mechanisms of the reactions of 4-alkyloxazolidinediones (1) (N-carboxy α-amino acid anhydrides(NCAs)) with α-amino acid benzyl ester p-toluenesulfonates (2) were investigated in acetonitrile containing triethylamine at low and room temperatures.Two types of reactions were observed: (1) the polymerization of NCAs was initiated with a small amount of 2 to produce polypeptides (6), and (2) the dipeptide benzyl esters (4) were produced by the stepwise reaction of NCAs with the esters.Both the polymerization and the dipeptide formation (1+2) seemed to be initiated by the nucleophilic attack of the amino group of the ester on the C-5 carbon of NCAs.The polymerization proceeded when the side chains of the amino acid esters (R2) were more bulky than those of the NCAs (R1).On the contrary, dipeptide esters were produced when the side chains of the NCAs (R1) were more bulky than those of the esters (R2).
- Oya, Masanao,Takahashi, Tomoko
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p. 2705 - 2707
(2007/10/02)
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