Conformationally engineering flexible peptides on silver nanoparticles

Jia, Xu; Gao, Tiange; Sheng, Lingjie; Wang, Yan; Lou, Chenxi; Wang, Haifang; Liu, Yuanfang; Cao, Aoneng

doi:10.1016/j.isci.2022.104324

Cited by 5 publications

(6 citation statements)

References 51 publications

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“…These inhibition results are also confirmed by the binding of the AuNP- x PEG/biotin/Pep1 and AuNP- x PEG/biotin/Pep1s with lysozyme as measured by SPR experiments (Figure B and Figure S4), which also show that the interaction between the negative control (AuNP- x PEG/biotin/Pep1s) and lysozyme becomes weaker with the increase of the PEG coverage on the surface of AuNPs, and 500 PEGs per AuNP (14 nm) is the optimal number to assist the restoration of the native conformation of Pep1 (as reflected by the binding and inhibition of lysozyme). Thus, the optimal number of PEGs plays the same role as the optimal number of Pep1 in helping Pep1 restore its native conformation, likely by imposing a suitable restriction on the movement of the reduced number of Pep1 on AuNPs to achieve a favorable entropic effect. ,,, Too low coverage of PEG will give Pep1 too much freedom to move on the surface of AuNPs and to adopt a large number of different conformations; thus, Pep1 cannot maintain its native conformation on AuNPs. On the other hand, an excess amount of PEG will make the surface of AuNPs too crowded, thus hindering the formation of the native conformation of Pep1.…”

Section: Resultsmentioning

confidence: 97%

“…Second, the surface of “bare” AuNPs can strongly bind with almost any proteins, , and thus the surface of AuNPs has to be functionalized with Pep1 or other hydrophilic molecules to prevent this non-specific binding. As estimated previously, the minimum surface coverage to reduce the strong non-specific binding of AuNPs is about one-fourth of the optimal density for restoring the native conformation of Pep1. , To fill these two roles, we used HS-PEG-SH to passivate the large bare surface of AuNPs left by reducing Pep1 and optimized the density of PEG on AuNPs to help the restoration of the native conformation of Pep1 by restriction of the movement (conformational space) of Pep1 on AuNPs to achieve a favorable entropic effect. ,,, …”

Section: Resultsmentioning

confidence: 99%

“…26,28 To fill these two roles, we used HS-PEG-SH to passivate the large bare surface of AuNPs left by reducing Pep1 and optimized the density of PEG on AuNPs to help the restoration of the native conformation of Pep1 by restriction of the movement (conformational space) of Pep1 on AuNPs to achieve a favorable entropic effect. 26,28,42,43 Pep1 is adapted from the CDR3 fragment of a monoclonal anti-lysozyme antibody, cAb-Lys3, with a Cys residue at its both terminals, so Pep1 conjugates to AuNPs with two Au−S bonds, which is critical to restoring its native conformation on AuNPs. 26,44 The HS-PEG-SH, like Pep1, was also anchored to AuNPs through two Au−S bonds, and it could passivate the bare AuNP surface and help Pep1 to form the correct conformation.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

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Biotinylated Au Nanoparticle-Based Artificial Antibody for Detection of Lysozyme by the Lateral Flow Immunoassay and Enzyme-Linked Immunosorbent Assay

Gao

Lou

et al. 2022

ACS Appl. Nano Mater.

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Antibody-based immunoassays such as the lateral flow immunoassay (LFIA) and enzyme-linked immunosorbent assay (ELISA) are currently indispensable analytical methods widely used in many fields, mainly due to the high sensitivity and specificity of antibodies. However, the high cost of monoclonal antibodies and their susceptibility to high temperature limit the application of immunoassays. Previously, we developed a class of gold nanoparticle (AuNP)-based artificial antibodies, called Goldbody. Goldbodies not only bind antigens as specifically as monoclonal antibodies do but also have far better stability than monoclonal antibodies. To take advantage of the excellent specificity, stability, and easy functionalization of Goldbodies and use them for the substitution of monoclonal antibodies in immunoassays, herein, we synthesize a biotinylated anti-lysozyme Goldbody and successfully construct a competitive LFIA for the detection of lysozyme in the range of 17.98–226.49 ng·mL–1. At the same time, the biotinylated anti-lysozyme Goldbody can easily replace the detection antibody in the commercial BA (biotinylated antibody)-ELISA kit for the detection of lysozyme with a lower detection limit of 0.34 ng·mL–1 and a wider detection range of 0.89–20 ng·mL–1 compared with the commercial BA-ELISA kit. In addition, the biotinylated anti-lysozyme Goldbody has good thermal stability in both assays and can accurately detect spiked samples even after pretreatment at 100 °C, demonstrating the high potential of Goldbodies as a good replacement of monoclonal antibodies in immunoassays.

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Section: Resultsmentioning

confidence: 97%

Section: Resultsmentioning

confidence: 99%

Section: ■ Results and Discussionmentioning

confidence: 99%

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Biotinylated Au Nanoparticle-Based Artificial Antibody for Detection of Lysozyme by the Lateral Flow Immunoassay and Enzyme-Linked Immunosorbent Assay

Gao

Lou

et al. 2022

ACS Appl. Nano Mater.

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“…NPs that are suitable for grafting peptides are not limited to AuNPs. As we demonstrated recently, AgNPs are also suitable to be used to produce AgNP-based artificial antibodies . In fact, many metal NPs with suitable mobility of the adatoms are also possible candidates for the scaffolds. − …”

Section: Resultsmentioning

confidence: 99%

“…As we demonstrated recently, AgNPs are also suitable to be used to produce AgNP-based artificial antibodies. 57 In fact, many metal NPs with suitable mobility of the adatoms are also possible candidates for the scaffolds. 58−60 Besides providing mobility for the anchoring positions of the grafted peptides, the NPs also contribute to the stability of native conformation of the peptides from two aspects.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Folding of Flexible Protein Fragments and Design of Nanoparticle-Based Artificial Antibody Targeting Lysozyme

Wang

Gao

et al. 2022

J. Phys. Chem. B

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It is generally believed that a protein’s sequence solely determines its native structure, but how the long- and short-range interactions jointly determine the native structure/conformation of the protein or every local fragment of the protein is still not fully understood. Since most protein fragments are unstructured on their own, direct observation of the folding of flexible protein fragments is very difficult. Interestingly, we show that it is possible to graft the complementary-determining regions (CDRs) of antibodies onto the surface of a gold nanoparticle (AuNP) to create AuNP-based artificial antibodies (denoted as Goldbodies), such as an antilysozyme Goldbody. Goldbodies can specifically recognize the corresponding antigens like the original natural antibodies do, but direct structural evidence for the refolding or restoration of native conformation of the grafted CDRs on AuNPs is still missing and in high demand. Herein we design a new Goldbody that targets an epitope on the lysozyme different from that of the previous antilysozyme Goldbody, and the one circle of helix in the CDR makes it possible to distinguish the unfolded conformation of the free CDR and its folded conformation on AuNPs by circular dichroism (CD) spectroscopy. The refolding of flexible protein fragments on NPs provides unique evidence and inspiration for understanding the fundamental principles of protein folding.

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