Resin Chromatography Research Articles

Tailoring polishing steps for effective removal of polysorbate-degrading host cell proteins in antibody purification.

Ensuring the quality and safety of biopharmaceutical products requires the effective separation of monoclonal antibodies (mAbs) from host cell proteins (HCPs). A major challenge in this field is the enzymatic hydrolysis of polysorbates (PS) in drug products. This study addresses this issue by investigating the removal of polysorbate-degrading HCPs during the polishing steps of downstream purification, an area where knowledge about individual HCP behavior is still limited. We investigated the separation of different mAb formats from four individual polysorbate degrading hydrolases (CES1F, CES2C, LPLA2, and PAF-AH) using cation exchange (CEX) and mixed-mode chromatography (MMC) polishing steps. Our research identified a key challenge: The similar elution behavior of mAbs and HCPs during chromatographic separation. To investigate this phenomenon, we performed high-throughput binding screenings for recombinant polysorbate degrading hydrolases and representative mAb candidates on CEX and MMC chromatography resins. We then employed a three-step strategy that also served as a scale-up process, optimizing separation conditions and leading to the successful removal of specific HCPs while maintaining high mAb recovery rates (>96%). This strategy involved the use of surface response models and miniature columns for screening, followed by validation on larger columns using a chromatography system. Our results highlight the critical role of the inherent properties of mAbs for successful separation from HCPs. These results underscore the need to tailor the purification process to leverage the slight differences in binding behavior and elution profiles between mAbs and specific HCPs. This approach lays the foundation for developing more effective strategies for overcoming the challenge of enzymatic polysorbate degradation, paving the way for improved quality and safety in biopharmaceutical products.

Anti-pulmonary fibrosis activity analysis of methyl rosmarinate obtained from Salvia castanea Diels f. tomentosa Stib. using a scalable process.

Pulmonary fibrosis is a progressive, irreversible, chronic interstitial lung disease associated with high morbidity and mortality rates. Current clinical drugs, while effective, do not reverse or cure pulmonary fibrosis and have major side effects, there are urgent needs to develop new anti-pulmonary fibrosis medicine, and corresponding industrially scalable process as well. Salvia castanea Diels f. tomentosa Stib., a unique herb in Nyingchi, Xizang, China, is a variant of S. castanea. and its main active ingredient is rosmarinic acid (RA), which can be used to prepare methyl rosmarinate (MR) with greater drug potential. This study presented an industrially scalable process for the preparation of MR, which includes steps such as polyamide resin chromatography, crystallization and esterification, using S. castanea Diels f. tomentosa Stib. as the starting material and the structure of the product was verified by NMR technology. The anti-pulmonary fibrosis effects of MR were further investigated in vivo and in vitro. Results showed that this process can easily obtain high-purity RA and MR, and MR attenuated bleomycin-induced pulmonary fibrosis in mice. In vitro, MR could effectively inhibit TGF-β1-induced proliferation and migration of mouse fibroblasts L929 cells, promote cell apoptosis, and decrease extracellular matrix accumulation thereby suppressing progressive pulmonary fibrosis. The anti-fibrosis effect of MR was stronger than that of the prodrug RA. Further study confirmed that MR could retard pulmonary fibrosis by down-regulating the phosphorylation of the TGF-β1/Smad and MAPK signaling pathways. These results suggest that MR has potential therapeutic implications for pulmonary fibrosis, and the establishment of this scalable preparation technology ensures the development of MR as a new anti-pulmonary fibrosis medicine.

A green and simple method for enrichment of major diterpenoids from the buds of Wikstroemia chamaedaphne with macroporous resins and their activation of latent human immunodeficiency virus activity

In this study, a green and efficient enrichment method for the four majors active diterpenoid components: pimelotide C, pimelotide A, simplexin, and 6α,7α-epoxy-5β-hydroxy-12-deoxyphorbol-13-decanoate in the buds of Wikstroemia chamaedaphne was established using macroporous resin chromatography. The adsorption and desorption rates of seven macroporous resins were compared using static tests. The D101 macroporous resin exhibited the best performance. Static and dynamic adsorption tests were performed to determine the enrichment and purification of important bioactive diterpenoids in the buds of W. chamaedaphne. Diterpenoid extracts were obtained by using D101 macroporous resin from the crude extracts of W. chamaedaphne. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis demonstrated that most of the diterpenoids were enriched in diterpenoid extracts. These results confirmed that diterpenoids in the buds of W. chamaedaphne could be enriched using macroporous resin technology, and the enriched diterpenoid extracts showed more efficient activation of the latent human immunodeficiency virus. This study provides a novel strategy for discovering efficient and low-toxicity latency-reversing agents and a potential basis for the comprehensive development and clinical application of the buds of W. chamaedaphne.

Modeling Chromatography Binding through Molecular Dynamics Simulations with Resin Fragments.

Accurate atomistic modeling of the interactions of a chromatography resin with a solute can inform the selection of purification conditions for a product, an important problem in the biotech and pharmaceutical industries. We present a molecular dynamics simulation-based approach for the qualitative prediction of interaction sites (specificity) and retention times (affinity) of a protein for a given chromatography resin. We mimicked the resin with an unrestrained ligand composed of the resin headgroup coupled with successively larger fragments of the agarose backbone. The interactions of the ligand with the protein are simulated in an explicit solvent using the Replica Exchange Molecular Dynamics enhanced sampling approach in conjunction with Hydrogen Mass Repartitioning (REMD-HMR). We computed the ligand interaction surface from the simulation trajectories and correlated the features of the interaction surface with experimentally determined retention times. The simulation and analysis protocol were first applied to a series of ubiquitin mutants for which retention times on Capto MMC resin are available. The ubiquitin simulations helped identify the optimal ligand that was used in subsequent simulations on six proteins for which Capto MMC elution times are available. For each of the six proteins, we computed the interaction surface and characterized it in terms of a range of simulation-averaged residue-level physicochemical descriptors. Modeling of the salt concentrations required for elution with respect to the descriptors resulted in a linear fit in terms of aromaphilicity and Kyte-Doolittle hydrophobicity that was robust to outliers, showed high correlation, and correctly ranked the protein elution order. The physics-based model building approach described here does not require a large experimental data set and can be readily applied to different resins and diverse biomolecules.

Separation of gold from irradiated actinide material utilizing a 2- thenoyltrifluoroacetone extraction resin

Post-detonation nuclear forensics capabilities depend on the ability to rapidly isolate radionuclides to improve measurement quality. In this work an extraction chromatography resin was developed utilizing thenoyltrifluoroacetone and 1-octanol supported on Eichrom prefilter resin. The resin was tested in nitric and hydrochloric acid matrices. In nitric acid the resin was able to extract zirconium, while in hydrochloric acid matrices it was possible to extract iron and gallium. In all acid conditions tested, gold was retained but can be eluted from the column with 10 % thiourea.

The Molecular Mechanism of FABP4 Inhibition Effects of GAS and 4-HBA in Gastrodia elata Blume Was Discussed Based on NMR and Molecular Docking.

To isolate gastrodin (GAS), 4-hydroxybenzyl alcohol (4-HBA), and phenolic compounds from Chinese medicine Gastrodia elata Blume, and to explore the binding mode of fatty acid binding protein 4 (FABP4/aP2) that is closely related to macrophage inflammation, we study their anti-inflammatory targets. After the ultrasonic extraction of the main active components with 70% ethanol, three resins and three eluents were selected, and eight phenolic monomers with similar structures, such as gastrodin and 4-hydroxybenzyl alcohol, were isolated from Gastrodia elata by AB-8 macroporous resin and silica gel column chromatography and eluted with the CHCl3-MeOH gradient. Their structures were identified by HPLC and nuclear magnetic resonance (NMR). The FABP4 protein was added to GAS and 4-HBA, and the NMR experiment was performed to observe ligand binding. Finally, according to the spectral information of STD-NMR and molecular docking technology, the interaction between ligands and protein was studied. The fluorescence competition experiment confirmed that both GAS and 4-HBA were in the binding cavity of FABP4. Moreover, 3-phenoxy-2-phenylbenzoic acid (PPA) is a possible inhibitor of FABP4, reducing macrophage-related inflammation and endoplasmic reticulum stress. This work provides a new basis for the anti-inflammatory mechanism of Gastrodia elata, paving the way for the research and development of FABP4 inhibitor drugs.

Hydrolytic purification of industrially extracted mimosa tannin

Tannins, which can be extracted from certain tree barks, are polyphenolic compounds, that gain a lot of interest in industry, as they can be utilized to replace petroleum-based chemicals. Currently, they are used in the leather industry, as flocculants or as adhesives. To further increase their potential, an increase in purity is necessary. To do so, various methods are available, in this study we present a 2-step approach consisting of (i) depolymerization and cleavage of glycosidic bonds and (ii) separation of phenolic-rich and phenolic-poor fractions. Commercially available mimosa tannin is treated with various concentrations of hydrochloric and sulfuric acid (0.4 M and 0.8 M) and separated with chromatographic resin. Resulting fractions are characterized by UV/Vis spectroscopy for phenolic content and antioxidant activity, infrared spectroscopy, NMR, HPLC-DAD and GPC to determine their composition and molecular size as well as their reactivity towards formaldehyde. It was observed that mild acidic cleavage with 0.4 M HCl results in more phenol-rich material (TPC 1124 µgGAE mg−1) while 0.8 M sulfuric acid leads to tannin fractions with higher antioxidative properties. Amberlite resin yields fractions with higher reactivity towards formaldehyde (gel time below 60 s compared to over 90 originally) while the Sephadex fractions present the highest values for total phenolic content.

Chromatography affinity resin with photosynthetically-sourced protein A ligand

Green, photosynthesizing plants can be proficiently used as cost-effective, single-use, fully biodegradable bioreactors for environmentally-friendly production of a variety of valuable recombinant proteins. Being near-infinitely scalable and most energy-efficient in generating biomass, plants represent profoundly valid alternatives to conventionally used stationary fermenters. To validate this, we produced a plastome-engineered tobacco bioreactor line expressing a recombinant variant of the protein A from Staphylococcus aureus, an affinity ligand widely useful in antibody purification processes, reaching accumulation levels up to ~ 250 mg per 1 kg of fresh leaf biomass. Chromatography resin manufactured from photosynthetically-sourced recombinant protein A ligand conjugated to agarose beads demonstrated the innate pH-driven ability to bind and elute IgG-type antibodies and allowed one-step efficient purification of functional monoclonal antibodies from the supernatants of the producing hybridomas. The results of this study emphasize the versatility of plant-based recombinant protein production and illustrate its vast potential in reducing the cost of diverse biotechnological applications, particularly the downstream processing and purification of monoclonal antibodies.

Exploring the effects of resin particle sizes on enhancing antibody binding capacity of a hybrid biomimetic ligand

Particle size is a critical parameter of chromatographic resins that significantly affects protein separation. In this study, effects of resin particle sizes (31.26 μm, 59.85 μm and 85.22 μm named Aga-31, Aga-60 and Aga-85, respectively) on antibody adsorption capacity and separation performance of a hybrid biomimetic ligand were evaluated. Their performance was investigated through static adsorption and breakthrough assays to quantify static and dynamic binding capacity (Qmax and DBC). The static adsorption results revealed that the Qmax for hIgG was 152 mg/g resin with Aga-31, 151 mg/g resin with Aga-60, and 125 mg/g resin with Aga-85. Moreover, the DBC at 10% breakthrough for hIgG with a residence time of 2 min was determined to be 49.4 mg/mL for Aga-31, 45.9 mg/mL for Aga-60, and 38.9 mg/mL for Aga-85. The resins with smaller particle sizes exhibited significantly higher capacity compared to typical commercial agarose resins and a Protein A resin (MabSelect SuRe). Furthermore, the Aga-31 resin with the hybrid biomimetic ligand demonstrated exceptional performance in terms of IgG purity (>98%) and recovery (>96%) after undergoing 20 separation cycles from CHO cell supernatant. These findings are helpful in further chromatographic resin design for the industrial application of antibody separation and purification.

Identification and characterization of rabbit scFv antibodies suitable for immuno-affinity separation of recombinant human kynureninase from Escherichia coli cell lysate

In this study we successfully developed an on-demand affinity chromatographic resin for manufacturing non-Fc-based biopharmaceuticals. Affinity chromatography columns with immobilized rabbit single-chain variable fragments (scFvs) were used for directly purifying the recombinant human kynureninase (KYNase) as a model target therapeutic protein from Escherichia coli cell lysates. Among the 38 different anti-KYNase scFv clones identified, four unique clones were selected as candidates for further characterization owing to their relatively low KYNase binding affinity at pH 4.0, thereby facilitating enzyme elution. Subsequently, all four clones were successfully produced and purified, followed by covalent coupling to NHS-activated HiTrap HP columns. While KYNase was specifically adsorbed to all four scFv-immobilized columns and was eluted at pH 4.0, the respective levels of static binding capacity (SBC) and recovery among the four scFv clones were different at this elution pH. That is, the scFv-immobilized columns captured KYNase with SBC ranging from 1.15 to 2.68 mg/cm3-bed with clone R2-47 exhibiting the highest level of SBC, with a ligand utilization of 39.4%. Moreover, using the scFv column of R2-47, 90.7% of the captured human KYNase was recovered in the first elution step at pH 4.0, and approximately 67% of enzymatic activity was retained. In summary, high-purity human KYNase was obtained from the E.coli cell lysate by one-step affinity purification, and 89.7% of KYNase was recovered in the first elution step. The methodology demonstrated in the current study could be applied for the purification and development of various therapeutic proteins.

GMP implementation of a hybrid continuous manufacturing process for a recombinant non-mAb protein-A case study.

Advances in manufacturing technology coupled with the increased potency of new biotherapeutic modalities have created an external environment where continuous manufacturing (CM) can address a growing need. Amgen has successfully implemented a hybrid CM process for a commercial lifecycle program. In this process, the bioreactor, harvest, capture column, and viral inactivation/depth filtration unit operations were integrated together in an automated, continuous module, while the remaining downstream unit operations took place in stand-alone batch mode. CM operations are particularly suited for so-called "high mix, low volume" manufacturing plants, where a variety of molecules are manufactured in relatively low volumes. The selected molecule fit this mold and was manufactured in a low-capital micro-footprint suite attached to an existing therapeutic production facility. Use of a hybrid process within an already operating facility required less capital and minimized complexity. To enable this hybrid CM process, an established fed-batch process was converted to a perfusion process with continuous harvest. Development efforts included both process changes and the generation of a novel cell line adapted to long-term perfusion. Chromatography resins were updated, and purification processes adapted to handle variable inputs due to the fluctuations in harvest titer from the lengthy production process. A novel automated single-use (SU) viral inactivation (VI) skid was introduced, which entailed the development of a robust pH verification and alarm system, along with procedures for product isolation to allow discard of specific cycles. The CM process demonstrated consistent performance, meaning it met predefined performance criteria (including product quality attributes, or PQAs) when operated within established process parameters and manufactured according to applicable procedures. Using a 75% reduction in scale, it resulted in a five-fold reduction in process media and buffer usage, a fifteen-fold increase in mass per thaw, and an overall process productivity increase of 45-fold (as measured by grams drug substance per liter per day.) The hybrid CM process also enabled increased material demand to be met with no change in cost of goods manufactured or plant capacity, due to the repurposing of existing facility space and the flexible duration of the hybrid CM harvest. Overall, the success of the hybrid CM platform represents an exciting opportunity to reduce costs and increase process efficiency in industry.

Flavonoids from Liriodendron chinense Leaves Alleviate Oxidative Activity in Vitro and D-galactose-induced Brain Injury via AMPK/SIRT1 Pathway in Vivo

The exploration of active ingredients and new activities of industrial crops could expand their scope of applications. Liriodendron chinense (L. chinense), an important ornamental and economic forest tree in China, has been widely used in timber, medicine and landscape. Flavonoids are major constituents of L. chinense leaves, while their effects of preventing brain damage are still unclear. In this study, flavonoids from L. chinense leaves (LCLF) were obtained through AB-8 resin chromatography and UPLC-MS/MS assay indicated that 16 compounds were identified from LCLF. LCLF treatment showed significant scavenging activities against DPPH•, ABTS•+, •OH, FRAP and total reducing power. D-galactose-impaired exploratory behaviors, cognitive functions and histopathological alterations in hippocampus of mice were obviously recovered by LCLF administration. Network pharmacology results demonstrated that LCLF could produce the healing efficacy through multiple pathways, mostly related to oxidative stress and inflammation. Further in vivo experiments revealed that LCLF treatment could regulated MDA content, SOD, CAT and GSH-Px activity, as well as the production of inflammatory factors (NO, IL-1β and IL-6). The underlying mechanisms of LCLF were probably related to Nrf2/HO-1, NF-κB and AMPK/SIRT1 pathways. Molecular docking results and surface plasmon resonance analysis validated that especially hesperidin in LCLF had strong binding activities with all 8 genes in the mentioned pathways. Our study revealed the beneficial effects of LCLF on oxidative activity and D-galactose-induced brain injury, offering experimental support for its potential application in pharmaceutical and other industries.

PH inactivation of SARS-CoV-2 and SARS-CoV in virus spiked protein A eluates from a mAb purification process

Biopharmaceutical manufacturing processes may include a low pH treatment step as a means of inactivating enveloped viruses. Small scale virus clearance studies are routinely performed using model enveloped viruses such as murine leukemia virus to assess inactivation at the pH range used in the downstream manufacturing process. Further, as a means of bioburden reduction, chromatography resins may be cleaned and stored using sodium hydroxide and this can also inactivate viruses. The susceptibility of SARS-CoV-2 and SARS-CoV to low pH conditions using protein A eluate derived material from a monoclonal antibody production process as well as high pH cleaning conditions was addressed. SARS-CoV-2 was effectively inactivated at pH 3.0, moderately inactivated at pH 3.4, but not inactivated at pH 3.8. Low pH was less effective at inactivating SARS-CoV. Both viruses were inactivated at a high pH of ca.13.4. These studies provide important information regarding the effectiveness of viral clearance and inactivation steps of novel coronaviruses when compared to other enveloped viruses.

Expression and purification of RNA Pseudouridylate synthase putative of malaria parasite (Plasmodium falciparum)

The high morbidity and mortality from malaria infection, especially amongst children under five years of age, necessitates the production of new antimalarial drugs. Plasmodium falciparum RNA pseudouridylate synthase putative (PfRPuSP) is an essential enzyme in protein synthesis, making it a potential drug target. Therefore, this study investigated the cloning, transformation, expression and purification of PfRPuSP. Both (pET28a (+) and pGEX-6P-1) plasmids were utilised for the cloning of PfRPuSP. The heat shock standard method was used for the gene constructs transformation in three strains of E. coli. Terrific and Luria Broth media at 25 °C and 30 °C were utilised to optimise the growth conditions. Nickel-nitrilotriacetate resin and fast protein liquid chromatography were employed for PfRPuSP purification to obtain its pure form. In this study, the best expression of PfRPuSP was achieved using PF3D7_1227900_ pET28a(+) construct in C41(DE3) competent cells overnight at 25 °C in LB medium as depicted by the Western blot results. The PF3D7_1227900_ pGEX-6P-1 construct yielded no desired result after expression and purification. The best medium, buffer, E.coli strain and matrix resin were determined, which can be used as baseline information for further studies and monitoring. These discoveries would be highly valuable in uncovering a way to form and understand the three-dimensional structure of PfRPuSP. This knowledge could lead to the development of medications that can block the enzyme in Plasmodium falciparum, ultimately aiding in eradicating malaria parasites.

Evaluation of chemical constituents of Draconis Sanguis and its protective effect on renal tubular injury in diabetic kidney disease

The chemical constituents of Draconis Sanguis were preliminarily studied by macroporous resin, silica gel, dextran gel, and high-performance liquid chromatography. One retro-dihydrochalcone, four flavonoids, and one stilbene were isolated. Their chemical structures were identified as 4-hydroxy-2,6-dimethoxy-3-methyldihydrochalcone(1), 4'-hydroxy-5,7-dimethoxy-8-methylflavan(2), 7-hydroxy-4',5-dimethoxyflavan(3),(2S)-7-hydroxy-5-methoxy-6-methylflavan(4),(2S)-7-hydroxy-5-methoxyflavan(5), and pterostilbene(6) by modern spectroscopy, physicochemical properties, and literature comparison. Compound 1 was a new compound. Compounds 2 and 6 were first found in the Arecaceae family. Compound 5 had the potential to prevent and treat diabetic kidney disease.

A new combined technology: Macroporous adsorption resin and high speed counter current chromatography for hydroxytyrosol separation from olive leaf enzymatic hydrolysate

Due to three free hydroxyl groups, hydroxytyrosol (HT) presents strong bioactivity and has broad food and drug application prospects. However, there is no good separation and purification technology. In this study, separation and purification technology of HT from the ethyl acetate extraction of enzymatic hydrolysate from olive leaf (EEEH) was investigated with macroporous adsorption resin (MAR) and high-speed counter-current chromatography (HSCCC) and the separation factors were optimized. First, the adsorption properties of eight MARs (AB-8, S-8, D-101, X-5, XAD-1, XAD-5, NKA-Ⅱ, H-103) for HT enrichment were studied. The results showed that H-103 macroporous resin was adsorbent, sample concentration was 1.5 mg/mL, eluent was 30 % ethanol solution, sample loading rate was 3.0 BV/h, elution velocity was 2.0 BV/h, and HT purity of EEEH was increased from 10.23 % to 40.78 %. Then, solvent systems were examined according to partition coefficients of target component and petroleum ether: ethyl acetate: methanol: water (4:6:4:6, v/v) system was chosen. The critical experimental parameters of HSCCC were optimized as following: revolution speed was 1200 rpm and flow rate was 3 mL/min. The HT purity of macroporous resin purified EEEH was increased from 40.78 % to 85.7 %. Therefore, MAR-HSCCC combined technology could be a very effective approach to separate and purify HT from EEEH.

Efficient actinide sequestration with ionic liquid-based extraction chromatography resins containing Aza-crown ether functionalized diglycolamides

Two new extraction chromatographic resins (ECRs) were prepared by impregnating two exotic diglycolamide (DGA) ligands (having three or four DGA moieties tethered to aza-crown ether scaffolds) dissolved in an ionic liquid onto an inert solid support. A room temperature ionic liquid (RTIL) was used for enhancing the performance of the ECRs. The ECR containing triaza-9-crown-3 functionalized with three DGA moieties (TAM-3-DGA), and tetraaza-12-crown-4 tethered with four DGA arms (TAM-4-DGA) were evaluated for the separation of Am3+ and Pu4+from nitric acid solutions. The resin capacity for Eu3+ was 9.52 mg/g and 7.24 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. Similarly, the resin capacity for Pu4+was 7.44 mg/g and 5.72 mg/g for TAM-3-DGA and TAM-4-DGA resins, respectively. These maximum loading values corresponded to the formation of a 1:1 metal/ligand complex for the Eu3+ ion and a 1:2 metal/ligand complex for the Pu4+ ion. The sorption of Eu3+and Pu4+on the resins followed a chemisorption phenomenon on both resins. The sorbed Eu3+and Pu4+ions from the resin phase could be efficiently desorbed with complexing ligands such as guanidine carbonate/HEDTA and oxalic acid, respectively.

Modeling the behavior of monoclonal antibodies on hydrophobic interaction chromatography resins

Monoclonal antibodies (mAbs) require a high level of purity for regulatory approval and safe administration. High-molecular weight (HMW) species are a common impurity associated with mAb therapies. Hydrophobic interaction chromatography (HIC) resins are often used to remove these HMW impurities. Determination of a suitable HIC resin can be a time and resource-intensive process. In this study, we modeled the chromatographic behavior of seven mAbs across 13 HIC resins using measurements of surface hydrophobicity, surface charge, and thermal stability for mAbs, and hydrophobicity and zeta-potential for HIC resins with high fit quality (adjusted R2 > 0.80). We identified zeta-potential as a novel key modeling parameter. When using these models to select a HIC resin for HMW clearance of a test mAb, we were able to achieve 60% HMW clearance and 89% recovery. These models can be used to expedite the downstream process development for mAbs in an industry setting.Graphical

Catch-and-Release: The Assembly, Immobilization, and Recycling of Redox-Reversible Artificial Metalloenzymes.

Technologies to improve the applicability of artificial metalloenzymes (ArMs) are gaining considerable interest; one such approach is the immobilization of these biohybrid catalysts on support materials to enhance stability and enable their retention, recovery, and reuse. Here, we describe the immobilization of polyhistidine-tagged ArMs that allow the redox-controlled replacement of catalytic cofactors that have lost activity, e.g., due to poisoning or decomposition, on immobilized metal affinity chromatography resins. By using periplasmic siderophore-binding protein scaffolds that originate from thermophilic bacteria (GstCeuE and PthCeuE) in combination with a siderophore-linked imine reduction catalyst, reaction rates were achieved that are about 3.5 times faster than those previously obtained with CjCeuE, the analogous protein of Campylobacter jejuni. Upon immobilization, the GstCeuE-derived ArM showed a decrease in turnover frequency in the reduction of dehydrosalsolidine by 3.4-fold, while retaining enantioselectivity (36%) and showing improved stability that allowed repeat recovery and recycling cycles. Catalytic activity was preserved over the initial four cycles. In subsequent cycles, a gradual reduction of activity was evident. Once the initial activity decreased to around 40% of the initial activity (23rd recycling cycle), the redox-triggered artificial cofactor release permitted the subsequent recharging of the immobilized protein scaffold with fresh, active cofactor, thereby restoring the initial catalytic activity of the immobilized ArM and allowing its reuse for several more cycles. Furthermore, the ArM could be assembled directly from protein present in crude cell extracts, avoiding time-consuming and costly protein purification steps. Overall, this study demonstrates that the immobilization of redox-reversible ArMs facilitates their "catch-and-release" assembly and disassembly and the recycling of their components, improving their potential commercial viability and environmental footprint.

Advancing multiproduct resin reuse for development and clinical manufacturing of an antibody-based therapeutic.

Chromatography resins used for purifying biopharmaceuticals are generally dedicated to a single product. For clinical manufacturing, this can result in resin being used only for a fraction of its potential lifetime. Extending the use of resins to multiple products can significantly reduce resin waste and cost. It can also improve manufacturing flexibility in case of raw material shortage during times such as the COVID-19 pandemic. The work presented herein describes an overarching multiproduct resin reuse (MRR) strategy, which includes a risk assessment, strategic planning, small-scale feasibility runs, and the successful execution of the MRR strategy to support Good manufacturing practice (GMP) clinical manufacturing of an antibody-based therapeutic. Specifically, an anion exchange (AEX) and cation exchange (CEX) MRR strategy is described. Clearance of carryover biological product is demonstrated by first cleaning the AEX and CEX manufacturing columns with sodium hydroxide to ensure inactivation and degradation of the carryover protein and followed by a blank buffer elution that is tested using various analytical methodologies to ensure reduction of the carryover protein to an acceptable level. To our knowledge, this is the first time an MRR approach has been successfully implemented and submitted to health authorities to support biologic GMP clinical manufacture.