Development of β-sheet structure in Aβ aggregation intermediates diminishes exposed hydrophobic surface area and enhances proinflammatory activity

Dhami, Kapur B.; Karki, Sanjib; Parks, Antanisha; Nichols, Cameron G.; Nichols, Michael R.

doi:10.1016/j.bbapap.2022.140817

Cited by 3 publications

(3 citation statements)

References 45 publications

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“…Studies have shown that the presence of exogenous signal peptides during pro-karyotic expression can affect proper protein expression (Freudl 2018 ; Chen et al 2023 ; Owji et al 2018 ), while removal of the hydrophobic region can effectively promote high-activity protein expression (Rego et al 2021 ; Dhami et al 2022 ). Previous studies found that expressing PlaS in E. coli BL21 significantly inhibited the growth of the host strain, resulting in very low protein expression levels and hindered purification of PlaS protein.…”

Section: Resultsmentioning

confidence: 99%

N-terminal truncated phospholipase A1 accessory protein PlaS from Serratia marcescens alleviates inhibitory on host cell growth and enhances PlaA1 enzymatic activity

Hu,

Liu,

Gan

et al. 2024

Bioresour. Bioprocess.

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Phospholipase A1 (PLA1) is a kind of specific phospholipid hydrolase widely used in food, medical, textile. However, limitations in its expression and enzymatic activity have prompted the investigation of the phospholipase-assisting protein PlaS. In this study, we elucidate the role of PlaS in enhancing the expression and activity of PlaA1 through N-terminal truncation. Our research demonstrates that truncating the N-terminal region of PlaS effectively overcomes its inhibitory effect on host cells, resulting in improved cell growth and increased protein solubility of the protein. The yeast two-hybrid assay confirms the interaction between PlaA1 and N-terminal truncated PlaS (∆N27 PlaS), highlighting their binding capabilities. Furthermore, in vitro studies using Biacore analysis reveal a concentration-dependent and specific binding between PlaA1 and ∆N27 PlaS, exhibiting high affinity. Molecular docking analysis provides insights into the hydrogen bond interactions between ∆N27 PlaS and PlaA1, identifying key amino acid residues crucial for their binding. Finally, the enzyme activity of PLA1 was boost to 8.4 U/mL by orthogonal test. Study significantly contributes to the understanding of the interaction mechanism between PlaS and PlaA1, offering potential strategies for enhancing PlaA1 activity through protein engineering approaches.

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Section: Resultsmentioning

confidence: 99%

N-terminal truncated phospholipase A1 accessory protein PlaS from Serratia marcescens alleviates inhibitory on host cell growth and enhances PlaA1 enzymatic activity

Hu,

Liu,

Gan

et al. 2024

Bioresour. Bioprocess.

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“…Aβ42 protofibril samples were analyzed as previously described (Dhami et al, 2022) without modification using a Jasco J‐1500 circular dichroism spectrometer measurements. Wavelength scan spectra represent the average of 20 accumulations for each Aβ sample.…”

Section: Methodsmentioning

confidence: 99%

“…Aβ protofibrils have been described as a non-spherical, filamentous, metastable intermediate (Kodali & Wetzel, 2007), and as small, curvilinear aggregates less than 100 nm in length (Paranjape et al, 2012;Walsh et al, 1997Walsh et al, , 1999. Soluble, diffusible protofibrils adopt a β-sheet secondary structure during their formation from random coil monomers (Dhami et al, 2022;Walsh et al, 1999), yet are polydisperse with respect to size (Nichols et al, 2015). Aβ protofibrils display a variety of detrimental biological activities including direct neurotoxicity, neuroinflammation, and disruption of cellular processes (Haass & Selkoe, 2007;Lannfelt et al, 2014;Paranjape et al, 2012;Yasumoto et al, 2019).…”

Section: Introductionmentioning

confidence: 99%

A new class of monoclonal Aβ antibodies selectively targets and triggers deposition of Aβ protofibrils

Grover

Pham

Jones

et al. 2023

Journal of Neurochemistry

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Aggregation and accumulation of amyloid‐β peptide (Aβ) are a critical trigger for the onset of Alzheimer's disease (AD). While the plaques are the most outstanding Aβ pathological feature, much of the recent research emphasis has been on soluble Aβ species because of their diffusible, proinflammatory, and toxic properties. The focus on soluble aggregated Aβ species has also increased the interest in antibodies that are selective for different Aβ conformations. In the current study, we developed and characterized a new class of monoclonal antibodies (referred to as mAbSL) that are selective for Aβ protofibrils. Cloning and sequencing of the heavy and light chain variable regions for multiple antibodies identified sequence characteristics that may impart the conformational selectivity by the antibodies. Transfection of FreeStyle 293F cells with the plasmids permitted in‐house expression and purification of mAbSL antibodies along with non‐conformation‐selective Aβ monoclonal antibodies (Aβ mAbs). Several of the purified mAbSL antibodies demonstrated significant affinity and selectivity for Aβ42 protofibrils compared with Aβ42 monomers and Aβ42 fibrils. Competition ELISA assays assessing the best overall antibody, mAbSL 113, yielded affinity constants of 7 nM for the antibody‐Aβ42 protofibril interaction, while the affinity for either Aβ42 monomers or Aβ42 fibrils was roughly 80 times higher. mAbSL 113 significantly inhibited Aβ42 monomer aggregation by a unique mechanism compared with the inhibition displayed by Aβ mAb 513. Aβ42 protofibril dynamics were also markedly altered in the presence of mAbSL 113, whereby insoluble complex formation and protofibril deposition were stimulated by the antibody at low substoichiometric molar ratios. As the field contemplates the therapeutic effectiveness of Aβ conformation‐selective antibodies, the findings presented here demonstrate new information on a monoclonal antibody that selectively targets Aβ protofibrils and impacts Aβ dynamics.

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Gut Microbiota Mediates Neuroinflammation in Alzheimer’s Disease: Unraveling Key Factors and Mechanistic Insights

Junyi,

Yueyang,

Bin

et al. 2024

Mol Neurobiol

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Development of β-sheet structure in Aβ aggregation intermediates diminishes exposed hydrophobic surface area and enhances proinflammatory activity

Cited by 3 publications

References 45 publications

N-terminal truncated phospholipase A1 accessory protein PlaS from Serratia marcescens alleviates inhibitory on host cell growth and enhances PlaA1 enzymatic activity

N-terminal truncated phospholipase A1 accessory protein PlaS from Serratia marcescens alleviates inhibitory on host cell growth and enhances PlaA1 enzymatic activity

A new class of monoclonal Aβ antibodies selectively targets and triggers deposition of Aβ protofibrils

Gut Microbiota Mediates Neuroinflammation in Alzheimer’s Disease: Unraveling Key Factors and Mechanistic Insights

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