A structure-affinity study of the amino acid side-chains in neurotensin : N and C terminal deletions and Ala-scan

Henry, Jenny A.; Horwell, David C.; Meecham, Ken; Rees, David C.

doi:10.1016/s0960-894x(00)80698-8

Cited by 35 publications

(35 citation statements)

References 13 publications

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“…Normally, amino acid scan/substitution and partial truncation of a parent peptide ligand are performed in order to determine the key residues involved in the biological activity of the peptide. In previous studies, alanine scanning of neurotensin revealed that leucine at position 13 confers high affinity binding (58). In these studies, alanine scanning mutagenesis of -TIA revealed that alanine substitution of phenylalanine at position 18 enhances the subtype selectivity of -TIA, while maintaining the noncompetitive nature and high affinity interaction of -TIA at ␣ 1B -ARs.…”

Section: Discussionmentioning

confidence: 95%

“…Charged residues within the peptide ligand have been shown to be important in peptide-receptor interactions. For example, alanine substitution of arginine at positions 8 or 9 resulted in a 10 -100-fold decrease in neurotensin binding affinity (58). Charged arginine residues at positions 4, 12, and 13 in -TIA appear to be important for conferring high affinity binding, as alanine substitution reduced the potency of -TIA at all three human ␣ 1 -AR subtypes by 6 -400-fold.…”

Section: Discussionmentioning

confidence: 99%

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Subtype-selective Noncompetitive or Competitive Inhibition of Human α1-Adrenergic Receptors by ρ-TIA

Chen

Rogge

Hague

et al. 2004

Journal of Biological Chemistry

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The 19-amino acid conopeptide ( -TIA) was shown previously to antagonize noncompetitively ␣ 1B -adrenergic receptors (ARs). Because this is the first peptide ligand for these receptors, we compared its interactions with the three recombinant human ␣ 1 -AR subtypes (␣ 1A , ␣ 1B , and ␣ 1D ). Radioligand binding assays showed that -TIA was 10-fold selective for human ␣ 1B -over ␣ 1A -and ␣ 1D -ARs. As observed with hamster ␣ 1B -ARs, -TIA decreased the number of binding sites (B max ) for human ␣ 1B -ARs without changing affinity (K D ), and this inhibition was unaffected by the length of incubation but was reversed by washing. However, -TIA had opposite effects at human ␣ 1A -ARs and ␣ 1D -ARs, decreasing K D without changing B max , suggesting it acts competitively at these subtypes. -TIA reduced maximal NE-stimulated [ 3 H]inositol phosphate formation in HEK293 cells expressing human ␣ 1B -ARs but competitively inhibited responses in cells expressing ␣ 1A -or ␣ 1D -ARs. Truncation mutants showed that the amino-terminal domains of ␣ 1B -or ␣ 1D -ARs are not involved in interaction with -TIA. Alanine-scanning mutagenesis of -TIA showed F18A had an increased selectivity for ␣ 1B -ARs, and F18N also increased subtype selectivity. I8A had a slightly reduced potency at ␣ 1B -ARs and was found to be a competitive, rather than noncompetitive, inhibitor in both radioligand and functional assays. Thus -TIA noncompetitively inhibits ␣ 1B -ARs but competitively inhibits the other two subtypes, and this selectivity can be increased by mutation. These differential interactions do not involve the receptor amino termini and are not because of the charged nature of the peptide, and isoleucine 8 is critical for its noncompetitive inhibition at ␣ 1B -ARs.

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Section: Discussionmentioning

confidence: 95%

Section: Discussionmentioning

confidence: 99%

Subtype-selective Noncompetitive or Competitive Inhibition of Human α1-Adrenergic Receptors by ρ-TIA

Chen

Rogge

Hague

et al. 2004

Journal of Biological Chemistry

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“…11,39 Next, we studied the effect of the amide-to-triazole substitution on the proteolytic stability of the conjugates. Thus, [ 177 Lu]-NT I−VII were incubated in human blood serum, and samples were analyzed at different time-points by γ-HPLC (see Experimental Procedures).…”

Section: Bioconjugate Chemistrymentioning

confidence: 99%

1,2,3-Triazole Stabilized Neurotensin-Based Radiopeptidomimetics for Improved Tumor Targeting

et al. 2015

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Neurotensin (NT) is a regulatory peptide with nanomolar affinity toward NT receptors, which are overexpressed by different clinically relevant tumors. Its binding sequence, NT(8-13), represents a promising vector for the development of peptidic radiotracers for tumor imaging and therapy. The main drawback of the peptide is its short biological half-life due to rapid proteolysis in vivo. Herein, we present an innovative strategy for the stabilization of peptides using nonhydrolizable 1,4-disubstituted, 1,2,3-triazoles as amide bond surrogates. A "triazole scan" of the peptide sequence yielded novel NT(8-13) analogues with enhanced stability, retained receptor affinity, and improved tumor targeting properties in vivo. The synthesis of libraries of triazole-based peptidomimetics was achieved efficiently on solid support by a combination of Fmoc-peptide chemistry, diazo transfer reactions, and the Cu(I)-catalyzed alkyne azide cycloaddition (CuAAC) employing methods that are fully compatible with standard solid phase peptide synthesis (SPPS) chemistry. Thus, the amide-to-triazole substitution strategy may represent a general methodology for the metabolic stabilization of biologically active peptides.

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“…Furthermore, once a structure of a natural ligand has been obtained, recognition properties towards the target molecule may be increased by determining the key amino acid residues that are involved in the biological activity. These studies may be performed by following strategies such as sequence truncation and amino acid scans [61,62]. Moreover natural ligand sequences can be used as starting point to prepare a first exploratory library or by using this sequence as scaffold where amino acids are altered.…”

Section: Design Of the Tailor-made Peptidementioning

confidence: 99%

Antibody-Like Peptides as a Novel Purification Tool for Drugs Design

Tozzi¹,

Giraudi²

2006

CPD

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New pharmaceutical approaches, such as biotechnology industry, genomic and proteomic studies, require the development of new analytical and preparative tools that should allow the resolution and the characterisation of complex sets of molecule mixtures in a high-throughput mode with the isolation of a single substance from complex matrices in a high degree of purity, low costs and wide availability. In this review we discuss the design of a tailor-made peptide by focusing our attention on the bioinformatic techniques and combinatorial approaches. Then synthesis, purification and characterisation of peptides with recognition properties are discussed by considering different approaches and their fitness to drug design. Moreover, the development of affinity devices and the discussion of their characteristics to optimise the purification phase are reported. Applications of peptide ligands that bind pharmaceutical compounds (i.e. therapeutic proteins, monoclonal antibodies, hormones) are described and analytical tools mentioned and evaluated. Future perspectives, in particular alternative applications of peptide ligands and their substitution with peptidomimetic compounds, are described.

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A structure-affinity study of the amino acid side-chains in neurotensin : N and C terminal deletions and Ala-scan

Cited by 35 publications

References 13 publications

Subtype-selective Noncompetitive or Competitive Inhibition of Human α1-Adrenergic Receptors by ρ-TIA

Subtype-selective Noncompetitive or Competitive Inhibition of Human α1-Adrenergic Receptors by ρ-TIA

1,2,3-Triazole Stabilized Neurotensin-Based Radiopeptidomimetics for Improved Tumor Targeting

Antibody-Like Peptides as a Novel Purification Tool for Drugs Design

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