Purpose: Thiol-disulfide exchange was monitored in recombinant human growth hormone (hGH) and in model tryptic peptides derived from hGH to investigate the effects of higher-order structure on the reaction.
Methods: Different free thiol-containing peptides, varying in length and amino acid sequence, were used to initiate the reaction at pH 7.0 and 37°C in hGH. Protein samples were digested with trypsin and analyzed for native disulfides, scrambled disulfides and free thiols using LC/MS. The loss of native disulfide and disulfide exchange was compared with model peptides derived from hGH.
Results: Loss of native disulfide in cyclic (cT20-T21) and linear peptides (T20-T21pep) derived from the C-terminal hGH disulfide during the first 60 min of reaction was greater than loss of the C-terminal disulfide in hGH itself. Of the thiols tested, glutathione (GSH) was the most reactive, forming the highest percentage of mixed disulfides in intact hGH and in the model peptides. At longer reaction times (>240 min), native disulfides in both hGH and cT20-T21 were regenerated. The fastest rates of regeneration were observed for Cys and the di- or tripeptide containing an Arg residue adjacent to Cys, suggesting that they may be useful in refolding.
Conclusions: Thiol-disulfide exchange reactions in hGH and related model peptides were influenced by higher order structure, by the size of the thiol reactant and by an Arg residue adjacent to Cys in the thiol reactant. Reduction of disulfide bonds in hGH did not affect higher order structure as measured by CD and HDX-MS.
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http://dx.doi.org/10.1007/s11095-016-1879-3 | DOI Listing |
Adv Healthc Mater
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Key Laboratory of Colloid and Interface Chemistry of the Ministry of Education, School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong, 250100, China.
Coacervates have garnered significant attention as potential drug carriers. However, the instability resulting from their intrinsic membrane-free nature restricts the application of coacervates in drug delivery. Herein, the engineering of poly(ethylene glycol) nanoparticles (PEG NPs) is reported using coacervates composed of PEG and polyphenols as the templates, where PEG is subsequently cross-linked based on different chemistries (e.
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February 2025
School of Pharmacy, Changzhou University, Changzhou, PR China.
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View Article and Find Full Text PDFInorg Chem
December 2024
Center for AIE Research, College of Materials Science and Engineering, Shenzhen University, Shenzhen 518060, China.
The ability of photosensitizers (PSs) to generate reactive oxygen species (ROS) is crucial for photodynamic therapy (PDT). However, many traditional PSs face the drawbacks that aggregation-caused quenching (ACQ) and highly expressed glutathione (GSH) in the tumor microenvironment seriously limit their ROS generation ability. Herein, we report two cationic dinuclear iridium complexes, and , which possess aggregation-induced emission (AIE).
View Article and Find Full Text PDFMAbs
October 2024
Department of Analytical Chemistry, Regeneron Pharmaceuticals, Inc, Tarrytown, NY, USA.
Non-reduced peptide mapping provides essential data for characterizing therapeutic monoclonal antibodies by isolating disulfide connections between specific cysteines. However, conventional digestive strategies used throughout the biopharmaceutical industry have been shown to cause unintentional rearrangement of disulfide connections (disulfide scrambling), thus generating connectivity profiles that do not accurately represent the protein being analyzed. Common misconceptions (e.
View Article and Find Full Text PDFJ Control Release
December 2024
School of Pharmaceutical Sciences, Key Laboratory of Biotechnology and Pharmaceutical Engineering, Wenzhou Medical University, Wenzhou, Zhejiang 325035, PR China; Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang 325000, PR China. Electronic address:
Basic fibroblast growth factor (bFGF) has proved to be effective for wound healing, yet its effectiveness is extremely retarded in diabetic wounds due to the severe oxidative stress in wound beds. To solve this issue, herein a novel combination therapy of bFGF and N-acetylcysteine (NAC, antioxidant) was devised for improved diabetic wound repair. To avoid rapid loss of both drugs in the wound beds, a bioresponsive hydrogel (bFGF-HSPP-NAC) was engineered by incorporating bFGF and NAC into polymer-drug conjugates (HSPP) via thiol-disulfide exchange reactions.
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