Changing an oxygen atom of the phosphoester bond in phosphopeptides by a sulfur atom enables instantly targeting Golgi apparatus (GA) and selectively killing cancer cells by enzymatic self‐assembly. ...Specifically, conjugating cysteamine S‐phosphate to the C‐terminal of a self‐assembling peptide generates a thiophosphopeptide. Being a substrate of alkaline phosphatase (ALP), the thiophosphopeptide undergoes rapid ALP‐catalyzed dephosphorylation to form a thiopeptide that self‐assembles. The thiophosphopeptide enters cells via caveolin‐mediated endocytosis and macropinocytosis and instantly accumulates in GA because of dephosphorylation and formation of disulfide bonds in Golgi by themselves and with Golgi proteins. Moreover, the thiophosphopeptide potently and selectively inhibits cancer cells (HeLa) with the IC50 (about 3 μM), which is an order of magnitude more potent than that of the parent phosphopeptide.
The rapid dephosphorylation of a thiophosphopeptide via the enzymatic reaction generates a self‐assembling thiopeptide that can target and accumulate at the Golgi apparatus for imaging Golgi and inhibiting cancer cells. This result illustrates a novel molecular platform for modulating functions resulted from enzymatic noncovalent synthesis.
Herein, we show intranuclear nanoribbons formed upon dephosphorylation of leucine‐rich L‐ or D‐phosphopeptide catalyzed by alkaline phosphatase (ALP) to selectively kill osteosarcoma cells. Being ...dephosphorylated by ALP, the peptides are first transformed into micelles and then converted into nanoribbons. The peptides/assemblies first aggregate on cell membranes, then enter cells via endocytosis, and finally accumulate in nuclei (mainly in nucleoli). Proteomics analysis suggests that the assemblies interact with histone proteins. The peptides kill osteosarcoma cells rapidly and are nontoxic to normal cells. Moreover, the repeated stimulation of the osteosarcoma cells by the peptides sensitizes the cancer cells rather than inducing resistance. This work not only illustrates a novel mechanism for nucleus targeting, but may also pave a new way for selectively killing osteosarcoma cells and minimizing drug resistance.
Upon the dephosphorylation of ALP, the leucine‐rich phosphopeptides self‐assemble into micelles and then convert into nanoribbons. The phosphopeptides/assemblies first aggregate on the cell membrane of osteosarcoma cells, and then enter cells via endocytosis, disrupt the nuclear membrane, and finally accumulate in nuclei by interaction with histone proteins to induce cell death.
Enzymatic noncovalent synthesis enables the spatiotemporal control of multimolecular crowding in cells, thus offering a unique opportunity for modulating cellular functions. This article introduces ...some representative enzymes and molecular building blocks for generating peptide assemblies as multimolecular crowding in cells, highlights the relevant biomedical applications, such as anticancer therapy, molecular imaging, trafficking proteins, genetic engineering, artificial intracellular filaments, cell morphogenesis, and antibacterial, and briefly discusses the promises of ENS as a multistep molecular process in biology and medicine.
This article highlights the unique features of enzymatic noncovalent synthesis (ENS) for generating multimolecular crowding in cells and the relevant applications for biomedicines.
Enzyme-instructed self-assembly (EISA) and hydrogelation is a versatile approach for generating soft materials. Most of the substrates for alkaline phosphatase catalysed EISA utilize phosphotyrosine ...(
p
Tyr) as the enzymatic trigger for EISA and hydrogelation. Here we show the first example of phosphonaphthyl (
p
NP) and phosphobiphenyl (
p
BP) motifs acting as faster enzymatic triggers than phosphotyrosine for EISA and hydrogelation. This work illustrates novel enzyme triggers for rapid enzymatic self-assembly and hydrogelation.
Phosphonaphthyl (
p
NP) or phosphobiphenyl (
p
BP), acting as both the N-terminal capping group and the enzymatic trigger of short peptides, results in alkaline phosphatase (ALP)-catalyzed gelation (almost) instantly.
Targeting immunosuppressive metastatic cancer cells is a key challenge in therapy. We recently have shown that a rigid‐rod aromatic, pBP−NBD, that responds to enzymes and kill immunosuppressive ...metastatic osteosarcoma (mOS) and castration resistant prostate cancer (CRPC) cells in mimetic bone microenvironment. However, pBP−NBD demonstrated moderate efficacy against CRPC cells. To enhance activity, we incorporated the unnatural amino acid L‐ or D‐4,4′‐biphenylalanine (L‐ or D−BiP) into pBP−NBD, drastically increasing cellular uptake and CRPC inhibition. Specifically, we inserted BiP into pBP−NBD to target mOS (Saos2 and SJSA1) and CRPC (VCaP and PC3) cells with overexpressed phosphatases. Our results show that the D‐peptide backbone with an aspartate methyl diester at the C‐terminal offers the highest activity against these immunosuppressive mOS and CRPC cells. Importantly, imaging shows that the peptide assemblies almost instantly enter the cells and accumulate primarily within the endoplasmic reticulum of Saos2, SJSA1, and PC3 cells and at the lysosomes of VCaP cells. By using BiP to boost cellular uptake and self‐assembly within cancer cells, this work illustrates an unnatural hydrophobic amino acid as a versatile and effective residue to boost endocytosis of synthetic peptides for intracellular self‐assembly.
This research demonstrates that the integration of unnatural amino acids (L‐ or D‐4,4′‐biphenylalanine) into peptide assemblies significantly accelerates their accumulation within prostate cancer cells, boosting their capacity to hinder cancer proliferation. This work paves a way for engineering supramolecular medicine, potentially heightening the efficacy of peptide‐based treatments for prostate cancer. It may lead to more effective therapeutic strategies for treating other cancers.
Although lipids contribute to cancer drug resistance, it is challenging to target diverse range of lipids. Here, we show enzymatically inserting exceedingly simple synthetic lipids into membranes for ...increasing membrane tension and selectively inhibiting drug resistant cancer cells. The lipid, formed by conjugating dodecylamine to d‐phosphotyrosine, self‐assembles to form micelles. Enzymatic dephosphorylation of the micelles inserts the lipids into membranes and increases membrane tension. The micelles effectively inhibit a drug resistant glioblastoma cell (T98G) or a triple‐negative breast cancer cell (HCC1937), without inducing acquired drug resistance. Moreover, the enzymatic reaction of the micelles promotes the accumulation of the lipids in the membranes of subcellular organelles (e.g., endoplasmic reticulum (ER), Golgi, and mitochondria), thus activating multiple regulated cell death pathways. This work, in which for the first time membrane tension is increased to inhibit cancer cells, illustrates a new and powerful supramolecular approach for antagonizing difficult drug targets.
A synthetic lipid is reported that self‐assembles to form micelles. Enzymatic dephosphorylation of the micelles inserts the lipids into membranes and increases membrane tension for effectively inhibiting cancer cells without inducing acquired drug resistance. This work, in which for the first time membrane tension is increased to inhibit cancer cells, illustrates a new and powerful supramolecular approach for antagonizing difficult drug targets.
Degradable biopolymers with functional groups play a crucial role in the biomedical field. In this case, the influences of temperature and pH values on the degradation performance of poly (γ‐glutamic ...acid) (γ‐PGA) were fully explored by gel permeation chromatography. Further, γ‐PGA‐Ca was prepared by using calcium chloride to react with the low molecular weight γ‐PGA and characterized by Fourier transform infrared, differential scanning calorimetry test, gel permeation chromatography, atomic absorption spectrophotometric, Ca2+ release in vivo, and cytotoxicity experiments. Furthermore, Caco‐2 cell model was constructed to study the mechanism of γ‐PGA‐Ca intestinal absorption. Results indicated that low pH value and high temperature are the suitable conditions for the degradation of γ‐PGA. It also suggested that γ‐PGA‐Ca can be used as calcium supplements due to its high rate of absorption.
Here, we report an apparently counterintuitive observation, in which a lower volume fraction of a branched peptide forms a stronger hydrogel after an enterokinase (ENTK) cleaves off the branch from ...the peptide. By varying the ratios of the branched peptide and ENTK and analysing the ratio of hydrogelator to precursor (H/P) in the enzymatic proteolysis reaction, our study shows that the H/P ratio controls the critical strain of the hydrogel formed, through enzymatic cleavage of the branch from the peptide. This work demonstrates that emergent properties (
e.g.
, hydrogelation) of peptide assemblies, resulting from enzymatic noncovalent synthesis (ENS), are context-dependent, while also providing insights for developing dynamic soft materials
via
ENS.
Here, we report an apparently counterintuitive observation, in which a lower volume fraction of a branched peptide forms a stronger hydrogel after an enterokinase (ENTK) cleaves off the branch from the peptide.
Herein, we show intranuclear nanoribbons formed upon dephosphorylation of leucine‐rich L‐ or D‐phosphopeptide catalyzed by alkaline phosphatase (ALP) to selectively kill osteosarcoma cells. Being ...dephosphorylated by ALP, the peptides are first transformed into micelles and then converted into nanoribbons. The peptides/assemblies first aggregate on cell membranes, then enter cells via endocytosis, and finally accumulate in nuclei (mainly in nucleoli). Proteomics analysis suggests that the assemblies interact with histone proteins. The peptides kill osteosarcoma cells rapidly and are nontoxic to normal cells. Moreover, the repeated stimulation of the osteosarcoma cells by the peptides sensitizes the cancer cells rather than inducing resistance. This work not only illustrates a novel mechanism for nucleus targeting, but may also pave a new way for selectively killing osteosarcoma cells and minimizing drug resistance.
Upon the dephosphorylation of ALP, the leucine‐rich phosphopeptides self‐assemble into micelles and then convert into nanoribbons. The phosphopeptides/assemblies first aggregate on the cell membrane of osteosarcoma cells, and then enter cells via endocytosis, disrupt the nuclear membrane, and finally accumulate in nuclei by interaction with histone proteins to induce cell death.
Multiparameter flow cytometry (MFC)-based minimal residual disease has been a poor predictor of prognosis in children with acute myeloid leukemia (AML). This study aimed to evaluate the incremental ...value of serial monitoring by droplet digital PCR (ddPCR) in forecasting the outcome of AML. Twenty-four children with AML were enrolled and the relapse-free survival (RFS) rate was estimated using the Kaplan–Meier method. Survival estimates were compared using the log-rank test. Survival analysis showed that the RFS rate in the ddPCR ≥ 0.1% group was significantly lower than that in the < 0.1% group (35.7% ± 19.8% vs. 83.6% ± 10.8%,
P
= 0.003). Moreover, serial monitoring by ddPCR showed that some mutations remained positive in some patients even though other co-mutations were eliminated, and those patients were more prone to relapse, with a significantly poorer RFS compared to patients negative for mutation (22.0% ± 19.2% vs 83.3% ± 11.3%,
P
= 0.001). Consequently, ddPCR may assist in prognostic forecasting for pediatric AML.
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