8 documents found, page 1 of 1
Lysine-PEGylated Cytochrome C with Enhanced Shelf-Life Stability
Santos, João H. P. M.; Feitosa, Valker A.; Meneguetti, Giovanna P.; Carretero, Gustavo; Coutinho, João A. P.; Ventura, Sónia P. M.Cytochrome c (Cyt-c), a small mitochondrial electron transport heme protein, has been employed in bioelectrochemical and therapeutic applications. However, its potential as both a biosensor and anticancer drug is significantly impaired due to poor long-term and thermal stability. To overcome these drawbacks, we developed a site-specific PEGylation protocol for Cyt-c. The PEG derivative used was a 5 kDa mPEG-NHS...
Building better biobetters: from fundamentals to industrial application
Torres-Obreque, Karin M.; Meneguetti, Giovanna P.; Muso-Cachumba, Jorge J.; Feitosa, Valker A.; Santos, João H. P. M.; Ventura, Sónia P. M.Biological drugs or biopharmaceuticals off patent open a large market for biosimilars and biobetters, follow-on biologics. Biobetters, in particular, are new drugs designed from existing ones with improved properties such as higher selectivity, stability, half-life and/or lower toxicity/immunogenicity. Glycosylation is one of the most used strategies to improve biological drugs, nonetheless bioconjugation is an...
Influence of lysosomal protease sensitivity in the immunogenicity of the antitu...
Rodrigues, Mariane A.D.; Pimenta, Marcela V.; Costa, Iris M.; Zenatti, Priscila P.; Migita, Natacha A.; Yunes, José A.; Rangel-Yagui, Carlota O.Made available in DSpace on 2021-06-25T10:35:17Z (GMT). No. of bitstreams: 0 Previous issue date: 2020-12-01; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES); Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq); Ministério da Ciência, Tecnologia, Inovações e Comunicações; Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP); L-asparaginase (ASNase) from Escherichia ...
Imidazolium-based ionic liquids as adjuvants to form Polyethylene Glycol with S...
Santos, João H. P. M.; Martins, Margarida; Silva, Amanda R. P.; Cunha, Jheniffer R.; Rangel-Yagui, Carlota O.; Ventura, Sónia P. M.Aqueous biphasic systems (ABS) are biocompatible systems applied in the extraction of biomolecules. Despite the biocompatibility of polymers and, particularly polyethylene glycol (PEG), to form ABS, their limitation in terms of phase separation is recognized. A new approach was recently proposed based on the use of ionic liquids (ILs) as adjuvants in ABS, enlarging the polarity range of these systems. Up to now...
PEGylation as an efficient tool to enhance cytochrome c thermostability: A kine...
Santos, João H. P. M.; Carretero, Gustavo; Ventura, Sónia P. M.; Converti, Attilio; Rangel-Yagui, Carlota O.Cytochrome-c from equine heart was kinetically and thermodynamically investigated either in its native (Cyt-c) or PEGylated forms with different PEGylation degrees (Cyt-c-PEG-4 and Cyt-c-PEG-8). Maximum activities were observed at 80 °C, and the irreversible deactivation was well described by first-order kinetics. The results of activity at different temperatures were used to estimate the activation energy of t...
An integrated process combining the reaction and purification of PEGylated prot...
Santos, João H. P. M.; Mendonça, Carlos M. N.; Silva, Amanda R. P.; Oliveira, Ricardo P. S.; Pessoa, Adalberto; Coutinho, João A. P.A downstream process combining PEGylation reaction and the use of enzyme conjugates acting as phase-forming components of aqueous biphasic systems (ABS) is proposed here. In this approach, citrate buffer (pH = 7.0) was used simultaneously to stop the reaction (avoiding the use of hydroxylamine) and as a phase forming agent inducing the phase separation of the PEGylated proteins. The partition of the bioconjugat...
Continuous separation of cytochrome-c PEGylated conjugates by fast centrifugal ...
Santos, João H. P. M.; Ferreira, Ana M. C.; Almeida, Mafalda R.; Quinteiro, Paula S. G. N.; Dias, Ana C. R. V.; Coutinho, João A. P.; Freire, Mara G.Herein, the effective use of aqueous biphasic systems (ABS) in Fast Centrifugal Partition Chromatography (FCPC) for the purification of PEGylated cytochrome c conjugates is shown. High recoveries (between 88% and 100%) and purities (∼100%) were obtained. Both the unreacted cytochrome c and solvents may be recovered and reused, thus allowing the design of a sustainable process in a continuous regime for the isol...
Multistep purification of cytochrome c PEGylated forms using polymer-based aque...
Santos, João H. P. M.; Carretero, Gustavo; Coutinho, João A. P.; Rangel-Yagui, Carlota O.; Ventura, Sónia P. M.Chemical PEGylation of proteins has been used to improve their physicochemical properties and kinetics. However, the PEGylation reactions lead to a heterogeneous mixture of PEGylated conjugates and unreacted protein, which is a challenge for the design of an efficient downstream process. The purification of PEGylated proteins should address the two main issues: the separation of PEGylated conjugates from the un...