ADAna Cristina Dias-Cabral

Ana Cristina Dias-Cabral

*This is an algorithmically generated author record based on publicly available information.

Current Organizations / Institutes

The organizations/institutes from the scholar's latest article


Ana Cristina Dias-Cabral has a total of 70 co-authors. Here are the top co-authors by number of shared publications:


Latest Publications

  • Open Access

    Unleashing the power of responsible knowledge management: A catalyst for sustainable business transformation

    by Raysa Geaquinto Rocha, Arminda Paco, Helena Alves, Cristina Dias-Cabral

    This study examines the impact of employees’ knowledge and competencies on the development of sustainable businesses through the lens of responsible knowledge management. We conducted a multinomial logistic regression using Flash Eurobarometer data to analyze the relationships among knowledge, competencies, and sustainability-related actions in the context of companies’ strategies and action plans. Our findings reveal that the absence of employees’ knowledge/competencies impedes the development of sustainable strategies. Additionally, isolated actions such as evaluation of the company’s impact on society, sustainable product or service development, and actions to save energy or switch to sustainable energy sources have a greater impact on the development of sustainable businesses than actions for involving employees in the management and actions to reduce impact or consumption on natural resources. Conversely, reuse or recycling actions have no significant impact. Thus, this research confirms and highlights the need for companies to prioritize knowledge management practices that incorporate sustainability-related competencies. By adopting a values-driven approach to knowledge management, organizations can unlock new avenues for growth, innovation, and competitive advantage while contributing to the larger goal of achieving sustainability. The contributions comprise providing empirical evidence supporting responsible knowledge management development and advancing with the convergence of a reframed knowledge management field and sustainability.


  • Insights on Alanine and Arginine Binding to Silica with Atomic Resolution

    by Stefan Rauwolf, Saientan Bag, Rodrigo Rouqueiro, Sebastian Patrick Schwaminger, Ana Cristina Dias-Cabral, Sonja Berensmeier, Wolfgang Wenzel

    Interactions of biomolecules with inorganic oxide surfaces such as silica in aqueous solutions are of profound interest in various research fields, including chemistry, biotechnology, and medicine. While there is a general understanding of the dominating electrostatic interactions, the binding mechanism is still not fully understood. Here, chromatographic zonal elution and flow microcalorimetry experiments were combined with molecular dynamic simulations to describe the interaction of different capped amino acids with the silica surface. We demonstrate that ion pairing is the dominant electrostatic interaction. Surprisingly, the interaction strength is more dependent on the repulsive carboxy group than on the attracting amino group. These findings are essential for conducting experimental and simulative studies on amino acids when transferring the results to biomolecule–surface interactions.


  • Mobile‐Phase Modulators as Salt Tolerance Enhancers in Phenylboronate Chromatography: Thermodynamic Evaluation of the Mechanisms Underlying the Adsorption of Monoclonal Antibodies

    by Sara A. S. L. Rosa, Alexandra Wagner, Cláudia L. da Silva, Maria R. Aires‐Barros, Ana M. Azevedo, Ana C. Dias‐Cabral

    Phenylboronate chromatography has been employed for bioseparation applications though details concerning the mechanisms of interaction between the ligand and macromolecules remain widely unknown. Here, the phenomena underlying the adsorption of an anti‐human interleukin‐8 (anti‐IL8) monoclonal antibody (mAb) onto an m‐aminophenylboronic acid (m‐APBA) ligand in the presence of different mobile‐phase modulators (NaF/MgCl 2/(NH 4) 2SO 4) and under different pH values (7.5/8.5/9.0) is investigated. Flow microcalorimetry (FMC) is applied to measure instantaneous heat energy transfer, providing insights about the role of specific and nonspecific interactions involved in the adsorptive process. Results show that the adsorption of anti‐IL8 mAb to m‐APBA is enthalpically driven, corroborating the presence of the reversible esterification reaction between boronic acid or boronates and cis‐diol‐containing molecules. Nevertheless, for all mobile‐phase modulators studied, changes in thermogram profiles are observed as well as reductions in the net heat of adsorption when increasing the pH. Overall, FMC and parallel chromatographic experiments data suggest that ligand salt tolerance could be enhanced using mobile‐phase modulators, with all salts studied promoting the specific cis‐diol interactions and reducing nonspecific interactions. The last feature is more noticeable at pH values above ligand's pK a, mainly due to the ability of NaF and (NH 4) 2SO 4 to diminish electrostatic interactions when compared to the commonly used NaCl.


  • Antibody Binding Heterogeneity of Protein A Resins

    by Gonçalo Fradique Lopes da Silva, Jacek Plewka, Rupert Tscheließnig, Helga Lichtenegger, Alois Jungbauer, Ana Cristina Mendes Dias‐Cabral

    Protein A affinity chromatography is a core unit operation in antibody manufacturing. Nevertheless, there is not enough understanding of in‐column antibody adsorption in the Protein A capture step. This work aims to investigate in situ the establishment of an antibody (trastuzumab) layer during Protein A chromatography both in terms of energetic contributions and uptake kinetics. Flow microcalorimetry is employed as a technique with an in situ operating detector, which provides an understanding of the thermodynamics of the adsorption process. In addition, the antibody uptake rate is also investigated in order to establish a correlation between its diffusion on the stationary phase and the associated thermodynamics. Two resins with different particle size, intraparticle porosity, and a Protein A ligand structure are studied: the synthetically engineered B‐domain tetrameric MabSelect SuRe and the synthetically engineered C‐domain hexameric TOYOPEARL AF‐rProtein A HC. The uptake rate follows a pore diffusion model at low equilibrium time, showing a slower diffusivity after a certain time because of the heterogeneous binding nature of these two resins. In addition, the microcalorimetric studies show that adsorption enthalpy is highly favourable at low isotherm concentrations and evolves toward an equilibrium with increasing surface concentration. These data suggest that the relationship between adsorption enthalpy and the establishment of the antibody layer in the Protein A chain is consistent with heterogeneous adsorption.


  • Open Access

    The pearl necklace model in protein A chromatography: Molecular mechanisms at the resin interface

    by Goncalo L. Silva, Jacek Plewka, Helga Lichtenegger, Ana C. Dias‐Cabral, Alois Jungbauer, Rupert Tscheließnig

    Staphylococcal protein A chromatography is an established core technology for monoclonal antibody purification and capture in the downstream processing. MabSelect SuRe involves a tetrameric chain of a recombinant form of the B domain of staphylococcal protein A, called the Z‐domain. Little is known about the stoichiometry, binding orientation, or preferred binding. We analyzed small‐angle X‐ray scattering data of the antibody–protein A complex immobilized in an industrial highly relevant chromatographic resin at different antibody concentrations. From scattering data, we computed the normalized radial density distributions. We designed three‐dimensional (3D) models with protein data bank crystallographic structures of an IgG1 (the isoform of trastuzumab, used here; Protein Data Bank: 1HZH) and the staphylococcal protein A B domain (the native form of the recombinant structure contained in MabSelect SuRe resin; Protein Data Bank: 1BDD). We computed different binding conformations for different antibody to protein A stoichiometries (1:1, 2:1, and 3:1) and compared the normalized radial density distributions computed from 3D models with those obtained from the experimental data. In the linear range of the isotherm we favor a 1:1 ratio, with the antibody binding to the outer domains in the protein A chain at very low and high concentrations. In the saturation region, a 2:1 ratio is more likely to occur. A 3:1 stoichiometry is excluded because of steric effects.


  • Open Access

    Antibody adsorption in protein‐A affinity chromatography – in situ measurement of nanoscale structure by small‐angle X‐ray scattering

    by Jacek Plewka, Gonçalo L. Silva, Rupert Tscheließnig, Harald Rennhofer, Cristina Dias‐Cabral, Alois Jungbauer, Helga C. Lichtenegger

    Protein‐A chromatography is the most widely used chromatography step in downstream processing of antibodies. A deeper understanding of the influence of the surface topology on a molecular/nanoscale level on adsorption is essential for further improvement. It is not clear if the binding is homogenous throughout the entire bead network. We followed the protein absorption process and observed the formation of a protein layer on fibers of chromatography resin in a time‐resolved manner in nanoscale. To characterize the changes in the antibody‐protein‐A ligand complex, small angle X‐ray scattering was employed using a miniaturized X‐ray‐transparent chromatography column packed with a MabSelect SuRe resin. Antibody‐free MabSelect SuRe resin fiber had an average radius of 12 nm and the protein layer thickness resulting from antibody adsorption was 5.5 and 10.4 nm for fiber and junctions, respectively under applied native conditions. We hypothesize that an average of 1.2 antibodies were adsorbed per protein‐A ligand tetramer bound to the outermost units. In contrast to previous studies, it was therefore possible for the first time to directly correlate the nanostructure changes inside the column, which is otherwise a black box, with the adsorption and elution process.