bims-cepepe 2024-05-26 papers

bims-cepepe

Biomed News

on Cell-penetrating peptides

Issue of 2024–05–26
eight papers selected by
Henry Lamb, Queensland University of Technology

Repurposing a plant peptide cyclase for targeted lysine acylation.
Enhancing Cellular Uptake of Native Proteins through Bio-Orthogonal Conjugation with Chemically Synthesized Cell-Penetrating Peptides.
Synthesis and Evaluation of Novel 68Ga-Labeled [D-Phe6,Leu13ψThz14]bombesin(6-14) Analogs for Cancer Imaging with Positron Emission Tomography.
Cystine-knot peptide inhibitors of HTRA1 bind to a cryptic pocket within the active site region.
Phospholipid Membrane Interactions of Model Ac-WL-X-LL-OH Peptides Investigated by Solid-State Nuclear Magnetic Resonance.
Actinium-225 targeted alpha particle therapy for prostate cancer.
The Transformative Role of 3D Culture Models in Triple-Negative Breast Cancer Research.
Structure-Activity Relationship of Synthetic Linear KTS-Peptides Containing Meta-Aminobenzoic Acid as Antagonists of α1β1 Integrin with Anti-Angiogenic and Melanoma Anti-Tumor Activities.

Nat Chem. 2024 May 24.

Repurposing a plant peptide cyclase for targeted lysine acylation.

Fabian B H Rehm, Tristan J Tyler, Yan Zhou, Yen-Hua Huang, Conan K Wang, Nicole Lawrence, David J Craik, Thomas Durek.

Transpeptidases are powerful tools for protein engineering but are largely restricted to acting at protein backbone termini. Alternative enzymatic approaches for internal protein labelling require bulky recognition motifs or non-proteinogenic reaction partners, potentially restricting which proteins can be modified or the types of modification that can be installed. Here we report a strategy for labelling lysine side chain ε-amines by repurposing an engineered asparaginyl ligase, which naturally catalyses peptide head-to-tail cyclization, for versatile isopeptide ligations that are compatible with peptidic substrates. We find that internal lysines with an adjacent leucine residue mimic the conventional N-terminal glycine-leucine substrate. This dipeptide motif enables efficient intra- or intermolecular ligation through internal lysine side chains, minimally leaving an asparagine C-terminally linked to the lysine side chain via an isopeptide bond. The versatility of this approach is demonstrated by the chemoenzymatic synthesis of peptides with non-native C terminus-to-side chain topology and the conjugation of chemically modified peptides to recombinant proteins.

DOI: https://doi.org/10.1038/s41557-024-01520-1
Pharmaceutics. 2024 May 03. pii: 617. [Epub ahead of print]16(5):

Enhancing Cellular Uptake of Native Proteins through Bio-Orthogonal Conjugation with Chemically Synthesized Cell-Penetrating Peptides.

Jekaterina Nebogatova, Ly Porosk, Heleri Heike Härk, Kaido Kurrikoff.

  The potential for native proteins to serve as a platform for biocompatible, targeted, and personalized therapeutics in the context of genetic and metabolic disorders is vast. Nevertheless, their clinical application encounters challenges, particularly in overcoming biological barriers and addressing the complexities involved in engineering transmembrane permeability. This study is dedicated to the development of a multifunctional nanoentity in which a model therapeutic protein is covalently linked to a cell-penetrating peptide, NickFect 55, with the objective of enhancing its intracellular delivery. Successful binding of the nanoentity fragments was achieved through the utilization of an intein-mediated protein-trans splicing reaction. Our research demonstrates that the fully assembled nanoentity-containing protein was effectively internalized by the cells, underscoring the potential of this approach in overcoming barriers associated with protein-based therapeutics for the treatment of genetic disorders.

Keywords:  bio-orthogonal conjugation; cell-penetrating peptides; protein therapeutics; protein transduction

DOI:  https://doi.org/10.3390/pharmaceutics16050617
Pharmaceuticals (Basel). 2024 May 11. pii: 621. [Epub ahead of print]17(5):

Synthesis and Evaluation of Novel 68Ga-Labeled [D-Phe6,Leu13ψThz14]bombesin(6-14) Analogs for Cancer Imaging with Positron Emission Tomography.

Lei Wang, Chao-Cheng Chen, Zhengxing Zhang, Hsiou-Ting Kuo, Chengcheng Zhang, Nadine Colpo, Helen Merkens, François Bénard, Kuo-Shyan Lin.

  Gastrin-releasing peptide receptor (GRPR) is overexpressed in various cancers and is a promising target for cancer diagnosis and therapy. However, the high pancreas uptake and/or metabolic instability observed for most reported GRPR-targeted radioligands might limit their clinical applications. Our group recently reported a GRPR-targeted antagonist tracer, [68Ga]Ga-TacsBOMB2 ([68Ga]Ga-DOTA-Pip-D-Phe6-Gln7-Trp8-Ala9-Val10-Gly11-His12-Leu13ψThz14-NH2), which showed a minimal pancreas uptake in a preclinical mouse model. In this study, we synthesized four derivatives with unnatural amino acid substitutions (Tle10-derived Ga-LW01158, NMe-His12-derived Ga-LW01160, α-Me-Trp8- and Tle10-derived Ga-LW01186, and Tle10- and N-Me-Gly11-derived Ga-LW02002) and evaluated their potential for detecting GRPR-expressing tumors with positron emission tomography (PET). The binding affinities (Ki(GRPR)) of Ga-LW01158, Ga-LW01160, Ga-LW01186, and Ga-LW02002 were 5.11 ± 0.47, 187 ± 17.8, 6.94 ± 0.95, and 11.0 ± 0.39 nM, respectively. [68Ga]Ga-LW01158, [68Ga]Ga-LW01186, and [68Ga]Ga-LW02002 enabled clear visualization of subcutaneously implanted human prostate cancer PC-3 tumor xenografts in mice in PET images. Ex vivo biodistribution studies showed that [68Ga]Ga-LW01158 had the highest tumor uptake (11.2 ± 0.65 %ID/g) and good tumor-to-background uptake ratios at 1 h post-injection. Comparable in vivo stabilities were observed for [68Ga]Ga-LW01158, [68Ga]Ga-LW01186, and [68Ga]Ga-LW02002 (76.5-80.7% remaining intact in mouse plasma at 15 min post-injection). In summary, the Tle10 substitution, either alone or combined with α-Me-Trp8 or NMe-Gly11 substitution, in Ga-TacsBOMB2 generates derivatives that retained good GRPR binding affinity and in vivo stability. With good tumor uptake and tumor-to-background imaging contrast, [68Ga]Ga-LW01158 is promising for detecting GRPR-expressing lesions with PET.

Keywords:  Gallium-68; antagonist; gastrin-releasing peptide receptor; pancreas uptake; positron emission tomography

DOI:  https://doi.org/10.3390/ph17050621
Nat Commun. 2024 May 22. 15(1): 4359

Cystine-knot peptide inhibitors of HTRA1 bind to a cryptic pocket within the active site region.

Yanjie Li, Yuehua Wei, Mark Ultsch, Wei Li, Wanjian Tang, Benjamin Tombling, Xinxin Gao, Yoana Dimitrova, Christian Gampe, Jakob Fuhrmann, Yingnan Zhang, Rami N Hannoush, Daniel Kirchhofer.

Cystine-knot peptides (CKPs) are naturally occurring peptides that exhibit exceptional chemical and proteolytic stability. We leveraged the CKP carboxypeptidase A1 inhibitor as a scaffold to construct phage-displayed CKP libraries and subsequently screened these collections against HTRA1, a trimeric serine protease implicated in age-related macular degeneration and osteoarthritis. The initial hits were optimized by using affinity maturation strategies to yield highly selective and potent picomolar inhibitors of HTRA1. Crystal structures, coupled with biochemical studies, reveal that the CKPs do not interact in a substrate-like manner but bind to a cryptic pocket at the S1' site region of HTRA1 and abolish catalysis by stabilizing a non-competent active site conformation. The opening and closing of this cryptic pocket is controlled by the gatekeeper residue V221, and its movement is facilitated by the absence of a constraining disulfide bond that is typically present in trypsin fold serine proteases, thereby explaining the remarkable selectivity of the CKPs. Our findings reveal an intriguing mechanism for modulating the activity of HTRA1, and highlight the utility of CKP-based phage display platforms in uncovering potent and selective inhibitors against challenging therapeutic targets.

DOI: https://doi.org/10.1038/s41467-024-48655-w
Membranes (Basel). 2024 May 01. pii: 105. [Epub ahead of print]14(5):

Phospholipid Membrane Interactions of Model Ac-WL-X-LL-OH Peptides Investigated by Solid-State Nuclear Magnetic Resonance.

Nicolai Etwin Alsaker, Øyvind Halskau, Bengt Erik Haug, Nathalie Reuter, Willy Nerdal.

  The role of aromatic amino acids in peripheral protein membrane binding has been reported to involve cation-π interactions with choline lipids. In this study, we have investigated the interactions of the model pentapeptide Ac-WL-X-LL-OH (where X = L, Y, F, or W) with the phospholipid membrane using solid-state NMR. The effect of guest residue X on the peptide-lipid interactome was complementary to the seminal report on the interfacial hydrophobicity scale by Wimley and White. We found that the phospholipids retained a lamellar phase in the presence of each of the peptides with an aromatic X residue, whereas the Leu peptide perturbed the bilayer to an extent where an additional isotropic phase was observed. The solid-state NMR 13C and 31P data provide additional information on the influence of these short peptides on the membrane that has not been previously reported. The magnitude of membrane perturbation was in the order of guest residue X = L > Y~F > W, which is consistent with the relative amino acid interfacial affinity reported by Wimley and White. Further work is, however, required to uncover the behavior of the peptide and localization in the membrane domain due to ambiguity of the 13C NMR data. We have launched efforts in this regard for the objective of better understanding the role of aromatic amino acids in peripheral membrane protein binding.

Keywords:  peptide–membrane interactions; phospholipid membranes; solid-state NMR

DOI:  https://doi.org/10.3390/membranes14050105
Theranostics. 2024 ;14(7): 2969-2992

Actinium-225 targeted alpha particle therapy for prostate cancer.

Anil P Bidkar, Luann Zerefa, Surekha Yadav, Henry F VanBrocklin, Robert R Flavell.

  Targeted alpha particle therapy (TAT) has emerged as a promising strategy for the treatment of prostate cancer (PCa). Actinium-225 (225Ac), a potent alpha-emitting radionuclide, may be incorporated into targeting vectors, causing robust and in some cases sustained antitumor responses. The development of radiolabeling techniques involving EDTA, DOTA, DOTPA, and Macropa chelators has laid the groundwork for advancements in this field. At the forefront of clinical trials with 225Ac in PCa are PSMA-targeted TAT agents, notably [225Ac]Ac-PSMA-617, [225Ac]Ac-PSMA-I&T and [225Ac]Ac-J591. Ongoing investigations spotlight [225Ac]Ac-hu11B6, [225Ac]Ac-YS5, and [225Ac]Ac-SibuDAB, targeting hK2, CD46, and PSMA, respectively. Despite these efforts, hurdles in 225Ac production, daughter redistribution, and a lack of suitable imaging techniques hinder the development of TAT. To address these challenges and additional advantages, researchers are exploring alpha-emitting isotopes including 227Th, 223Ra, 211At, 213Bi, 212Pb or 149Tb, providing viable alternatives for TAT.

Keywords:  Actinium-225; alpha particle therapy; prostate cancer; targeted alpha therapy

DOI:  https://doi.org/10.7150/thno.96403
Cancers (Basel). 2024 May 13. pii: 1859. [Epub ahead of print]16(10):

The Transformative Role of 3D Culture Models in Triple-Negative Breast Cancer Research.

Xavier S Bittman-Soto, Evelyn S Thomas, Madeline E Ganshert, Laura L Mendez-Santacruz, J Chuck Harrell.

  Advancements in cell culturing techniques have allowed the development of three-dimensional (3D) cell culture models sourced directly from patients' tissues and tumors, faithfully replicating the native tissue environment. These models provide a more clinically relevant platform for studying disease progression and treatment responses compared to traditional two-dimensional (2D) models. Patient-derived organoids (PDOs) and patient-derived xenograft organoids (PDXOs) emerge as innovative 3D cancer models capable of accurately mimicking the tumor's unique features, enhancing our understanding of tumor complexities, and predicting clinical outcomes. Triple-negative breast cancer (TNBC) poses significant clinical challenges due to its aggressive nature, propensity for early metastasis, and limited treatment options. TNBC PDOs and PDXOs have significantly contributed to the comprehension of TNBC, providing novel insights into its underlying mechanism and identifying potential therapeutic targets. This review explores the transformative role of various 3D cancer models in elucidating TNBC pathogenesis and guiding novel therapeutic strategies. It also provides an overview of diverse 3D cell culture models, derived from cell lines and tumors, highlighting their advantages and culturing challenges. Finally, it delves into live-cell imaging techniques, endpoint assays, and alternative cell culture media and methodologies, such as scaffold-free and scaffold-based systems, essential for advancing 3D cancer model research and development.

Keywords:  3D culture models; 3D culturing techniques; breast cancer; cell aggregates; extracellular matrix; organoids; patient-derived organoids; spheroids; triple-negative breast cancer

DOI:  https://doi.org/10.3390/cancers16101859
Pharmaceuticals (Basel). 2024 Apr 24. pii: 549. [Epub ahead of print]17(5):

Structure-Activity Relationship of Synthetic Linear KTS-Peptides Containing Meta-Aminobenzoic Acid as Antagonists of α1β1 Integrin with Anti-Angiogenic and Melanoma Anti-Tumor Activities.

Majdi Saleem Naamneh, Tatjana Momic, Michal Klazas, Julius Grosche, Johannes A Eble, Cezary Marcinkiewicz, Netaly Khazanov, Hanoch Senderowitz, Amnon Hoffman, Chaim Gilon, Jehoshua Katzhendler, Philip Lazarovici.

  To develop peptide drugs targeting integrin receptors, synthetic peptide ligands endowed with well-defined selective binding motifs are necessary. The snake venom KTS-containing disintegrins, which selectively block collagen α1β1 integrin, were used as lead compounds for the synthesis and structure-activity relationship of a series of linear peptides containing the KTS-pharmacophore and alternating natural amino acids and 3-aminobenzoic acid (MABA). To ensure a better stiffness and metabolic stability, one, two and three MABA residues, were introduced around the KTS pharmacophore motif. Molecular dynamics simulations determined that the solution conformation of MABA peptide 4 is more compact, underwent larger conformational changes until convergence, and spent most of the time in a single cluster. The peptides' binding affinity has been characterized by an enzyme linked immunosorbent assay in which the most potent peptide 4 inhibited with IC50 of 324 ± 8 µM and 550 ± 45 µM the binding of GST-α1-A domain to collagen IV fragment CB3, and the cell adhesion to collagen IV using α1-overexpressor cells, respectively. Docking studies and MM-GBSA calculations confirmed that peptide 4 binds a smaller region of the integrin near the collagen-binding site and penetrated deeper into the binding site near Trp1. Peptide 4 inhibited tube formation by endothelial cell migration in the Matrigel angiogenesis in vitro assay. Peptide 4 was acutely tolerated by mice, showed stability in human serum, decreased tumor volume and angiogenesis, and significantly increased the survival of mice injected with B16 melanoma cells. These findings propose that MABA-peptide 4 can further serve as an α1β1-integrin antagonist lead compound for further drug optimization in angiogenesis and cancer therapy.

Keywords:  KTS; MABA; angiogenesis; cell adhesion; conformation; integrin α1; melanoma tumor; modeling; peptide synthesis; stability

DOI:  https://doi.org/10.3390/ph17050549