02423nas a2200253 4500008004100000022001400041245009200055210006900147260000800216300001100224490000800235520158900243653002201832653002301854653002301877653002001900653003701920100001801957700002001975700002601995700001702021700001802038856011302056 2020 eng d a1369-703X00aUnderstanding unfolding and refolding of the antibody fragment (Fab). I. In-vitro study0 aUnderstanding unfolding and refolding of the antibody fragment F cDEC a1077640 v1643 a

In-vitro protein refolding is a major rate-limiting step in the large scale production of antibody fragments expressed using a microbial source like E. coli. This investigation is focused on understanding the in-vitro unfolding and refolding of the multi-domain protein involving inter-domain disulfide linkage, like antibody fragment (Fab). Solubilization behavior of the inclusion bodies and unfolding events of Fab fragment (Biosimilar rHu Ranibizumab) were studied using nano-differential scanning fluorimetry (nano-DSF). Fab unfolding behavior was studied by fitting experimental data with the two-state and three-state thermodynamic model. Based on the Fab unfolding understanding, a two-stage design of experiment (DoE) strategy was used for the optimization of the in-vitro refolding condition of a Fab fragment. Refolding yield of 56.03 +/- 1.15 % was achieved using the optimized oxidative refolding conditions maintained by appropriate dilution factor and redox reagent ratio. Refolding kinetics of the rHu Ranibizumab was analyzed using a three-parameter kinetic model showing rate constant k(1) :7.05e(-6) l/mg.min, k(2) :0.57 l/mg.min, and k(3) :310.19 l/mg.min. Based on observed refolding kinetics, it was concluded that the Fab refolding follows a three-state mechanism with the refolding intermediate/(s) formation from light and heavy chain of the Fab fragment as an overall rate-limiting step. The method described here is a useful tool to identify high-yield scalable refolding conditions for multi-domain proteins involving inter-domain disulfide bonds.

10aAntibody fragment10aIn-vitro refolding10aRefolding kinetics10arHu Ranibizumab10aTwo-state and Three-state models1 aGani, Kayanat1 aBhambure, Rahul1 aDeulgaonkar, Prashant1 aMehta, Deepa1 aKamble, Manoj uhttps://library.ncl.res.in/content/understanding-unfolding-and-refolding-antibody-fragment-fab-i-vitro-study02426nas a2200253 4500008004100000022001400041245018900055210006900244260000800313300001100321490000800332520147300340653002201813653002901835653002301864653002601887653002001913100001801933700002001951700002001971700003301991700002002024856012802044 2022 eng d a1369-703X00aUnderstanding unfolding and refolding of the antibody fragment (Fab) III: mapping covalent and non-covalent interactions during in-vitro refolding of light chain, heavy chain, and Fab.0 aUnderstanding unfolding and refolding of the antibody fragment F cNOV a1086440 v1873 a

In-vitro refolding of the antibody fragments from inclusion bodies is a critical manufacturing bottleneck. We have previously reported that Fab refolding involves the formation of an intermediate. To further decode the refolding pathway, we have mapped the covalent and non-covalent interactions during in-vitro refolding of individual light chain (LC), heavy chain (HC), and intact Fab. Intrinsic fluorescence analysis was performed to map the non -covalent interactions, whereas time-dependent disulfide mapping was performed using LC-MS/MS analysis under non-reducing and reducing atmospheres. Refolding of purified LC, HC, and intact Fab (Biosimilar rHu Ranibi-zumab) was investigated in the study. Under the reducing condition, LC, HC, and intact Fab required around 96, 30, and 70 h, respectively, whereas, under non-reducing conditions, they required only 48, 10, and 48 h, respectively, to acquire the native conformation. The disulfide bond mapping revealed that the bond between LC_Cys23/Cys88 is more unstable. The peptides mapped with the inter-chain disulfide bond were identified at 48 h during the refolding and can be considered as the rate-limiting step in (Fab) refolding. We have also studied a new refolding strategy involving assembly of separately refolded LC and HC into Fab molecule. In this case the Fab refolding yield was low (18.0 +/- 1.36%), indicating inefficient assembly of refolded LC and HC chain into native Fab molecule.

10aAntibody fragment10aDisulfide bond formation10aIn-vitro refolding10aLight and heavy chain10arHu Ranibizumab1 aGani, Kayanat1 aChirmade, Tejas1 aUghade, Santosh1 aThulasiram, Hirekodathakallu1 aBhambure, Rahul uhttps://library.ncl.res.in/content/understanding-unfolding-and-refolding-antibody-fragment-fab-iii-mapping-covalent-and-non02732nas a2200241 4500008004100000022001400041245012700055210006900182260000900251300001100260490000800271520191900279653001102198653002002209653002302229653001402252653001602266100001602282700002002298700002202318700002002340856013002360 2023 eng d a0141-813000aChromatography assisted in-vitro refolding and purification of recombinant peptibody: recombinant romiplostim a case study0 aChromatography assisted invitro refolding and purification of re cSEP  a1260370 v2493 a

In-vitro protein refolding is one of the key rate-limiting unit operations in manufacturing of fusion proteins such as peptibodies expressed using E. coli. Dilution-assisted refolding is the most commonly used industrial practice to achieve the soluble, native functional form of the recombinant protein from the inclusion bodies. This study is focused on developing a chromatography-assisted in-vitro refolding platform to produce the biologically active, native form of recombinant peptibody. Recombinant Romiplostim was selected as a model protein for the study. A plug flow tubular reactor was connected in series with capture step affinity chromatography to achieve simultaneous in-vitro refolding and capture step purification of recombinant Romiplostim. Effect of various critical process parameters like fold dilution, temperature, residence time, and Cysteine: DTT ratio was studied using a central composite based design of experiment strategy to achieve a maximum refolding yield of selected peptibody. Under optimum refolding conditions, the maximum refolding yield of 57.0 & PLUSMN; 1.5 % and a purity of over 79.73 & PLUSMN; 3.4 % were achieved at 25-fold dilution, 15 degrees C temperature, 6 h residence time with 6 mM and 10 mM of cysteine and DTT, respectively. The formation of native peptibody structure was examined using various orthogonal analytical tools to study the protein's primary, secondary, and tertiary structure. The amino acid sequence for the disulfide-linked peptide was mapped using collision-induced dissociation (CID) to confirm the formation of interchain disulfide bonds between Cys7-Cys7 and Cys10-Cys10 similarly for intra-chain disulfide bonds between Cys42-Cys102, and Cys148-Cys206. The developed protocol here is a valuable tool to identify high-yield scalable refolding conditions for multi-domain proteins involving inter-domain disulfide bonds.

10aCE-SDS10aDisulfide bonds10aIn-vitro refolding10aPeptibody10aRomiplostim1 aRana, Sunil1 aUghade, Santosh1 aKumthekar, Rupali1 aBhambure, Rahul uhttps://library.ncl.res.in/content/chromatography-assisted-vitro-refolding-and-purification-recombinant-peptibody-recombinant