Katarzyna Stapor

The issue of protein folding in vivo remains an unsolved problem despite important progress achieved by artificial intelligence (AlphaFold). Experimental studies have shown that there are several mechanisms involved in this process. The main distinction concerns the involvement of chaperone proteins in this process as opposed to spontaneous folding. Evolutionary analysis shows that tubulin in eukaryotic organisms requires engagement of the ATP-dependent ring-shaped chaperonin TRiC/CCT, while the homologous protein in prokaryotic organisms obtains its functional structure without the support from other proteins. This study—limited to 2 examples: one human tubulin β chain and one structure of homologous bacterial FtsZ protein—presents hypothetical interpretation of these differences based on the external conditions for folding process. The differences of the distribution of hydrophobicity in the compared proteins are taken as the criteria for comparison. The fuzzy oil drop model (FOD-M) assumes the folding of prokaryotic proteins as a spontaneous process aided only by the presence of the water environment that directs the folding toward the generation of a centrally located hydrophobic core with a polar surface. Eukaryotic protein—tubulin—exhibits a distribution of hydrophobicity that lacks this type of order as it is interpreted based on the FOD-M assumptions. The difference seems to be the result of the involvement of different external force fields in the folding process. These 2 proteins are an example that suggest the need to include the active influence of the local environment. The hypothesis for in silico methods of folding process simulation is assumed to use a multiple-object optimization technique that takes into account the optimization of the energy state of protein E as a function dependent on 2 functions: E _INT (internal force field) and E _EXT (external force field).

Stabilisation of very small proteins and very small domains (less than 50 aa) requires special methods. The stability of the III-order structure is ensured by the presence of hydrophobic core and/or SS-bonds. The contribution of the aqueous environment directing the formation of the III-order structure leads to a structure with a centric hydrophobic core and a polar surface. In similar fashion, the membrane environment directs the structuring of active proteins in the membrane envelope towards the exposure of hydrophobic residues on the surface with polar residues in the centre (ion channel). In addition to these two environments, other factors are identified critical to the formation of the III-order structure. These are chaperone proteins—chaperones or chaperonins. A very short polypeptide chain (below 50 aa) has a much lower number of degrees of freedom in achieving a stable three-dimensional structure. An example of proteins and domains with such a low composition are proteins/domains interacting with DNA referred to as Zn-fingers. Representatives of these proteins/domains (and others requiring the presence of Zn2 + ions) are analysed for hydrophobicity distribution in this paper. In these systems, the Zn2 + ion coordinating mainly Cys and His provides the presence of a centric hydrophobic core stabilising the system with exposed polarity. This is related to the formation of structures adapted to interact with DNA. For these proteins, a small domain size is additionally required to ensure the ability to interact with the corresponding grooves in the DNA structure. The analysis of protein groups containing Zn2 + ions was performed using a fuzzy oil drop model (FOD-M). A high degree of ordered hydrophobicity was demonstrated with a hydrophobic core present and a polar surface with a micelle-like distribution. This system, or arrangement, stabilises the structure in an aqueous environment in which the proteins operate.

Given the critical importance of preventing protein aggregation in neurodegenerative diseases, aggregation prediction tools are essential. Amyloid predictors would facilitate the understanding and exploitation of the amyloid state of proteins, providing an alternative to costly and slow laboratory tests. In recent years, hexapeptides have become a model for studying amyloid formation. Hexapeptides can also be used to identify aggregation‐prone regions in proteins, particularly those involved in amyloid formation. While numerous computational methods using sophisticated feature sets and architectures have been developed for classifying hexapeptides and predicting amyloidogenic regions in proteins, predictive performance remains limited; for instance, BAP achieves only 84% accuracy. Here, we designed a novel feature selection method for hexapeptides, resulting in an easy to interpret four‐feature representation called the AmyloPick model. A classifier based on this representation outperforms existing state‐of‐the‐art methods. When extended to detect aggregation‐prone regions (APRs) in full proteins, it performs comparably to established tools. A key contribution of this study is the statistical methodology that enables a rigorous performance assessment and direct comparison with other classifiers. This is particularly important because differing methodologies in the literature often hinder the comparability of the proposed methods. Our AmyloPick classifier significantly outperformed the state‐of‐the‐art Budapest Amyloid Predictor (BAP) across all metrics, particularly in adjusted geometric mean (AGM) (0.7808 vs. 0.7649 for BAP) and accuracy (0.8089 vs. 0.7955 for BAP). For APR identification, APR‐AmyloPick was comparable to ANuPP overall but significantly outperformed it in the metric. We have also developed a web server for the AmyloPick classifier.

The activity of serpins uses a specific mechanism or process. This process comprises several steps and is related to significant structural changes that involve significant displacement of chain fragments and whole molecules of protease. An important role is played by a segment of the serpin chain called the Reactive Central Loop (RCL), which interacts with the protease by inhibiting its activity. For the covalent binding of the protease to serpin, the movement of the protease molecule is an effect of splicing the RCL segment into beta-sheet A of serpin. There are structural forms—native, latent, Michaelis complex (non-covalent enzyme-inhibitor complex prior to RCL cleavage), covalent serpin–protease complex, and cleaved—associated with serpin activity. In this work, all these structural forms are discussed using the fuzzy oil drop (FOD-M) model, where the assessment criterion of structuring is based on identifying the type of hydrophobicity distribution. The analysis reveals the specificity of the inhibition mechanism, including the specific action of the RCL. The structural changes involved in this process have been shown to preserve the distribution of hydrophobicity in the form preferred by the aqueous environment in which serpins are active. The disorder (according to FOD-M model) in two complexes (Michaelis and covalent) is hypothetically treated as code for degradation factors. The applied model assesses the function-related structures using the hydrophobicity distribution as the criterion in contrast to many publications based on energetic aspects of serpin activity. Structural changes appear appropriate for water environments—the environment of serpin activity.

The research presented here was designed to look for possible relationships between personality traits, including temperament, work ethic components and workaholism. Workaholism, i.e., work addiction was conceptualized as obsession and compulsion to work and excessive work. The NEO-Five Factor Inventory and the Emotionality, Activity, Sociability-Temperament Survey were used to measure personality, including temperament. Work ethic was measured using the Multidimensional Work Ethic Profile, and workaholism was measured using the Dutch Work Addiction Scale. The survey was conducted at 2 time points 5 weeks apart. Predictors (personality, work ethic) were examined first and workaholism was examined after 5 weeks. A sample of 211 employees from various Polish organizations was surveyed. The results of the canonical analysis indicate that negative emotionality, a tendency to react with emotions such as dissatisfaction (distress), and selected components of work ethic - namely, perceiving work as a moral obligation, work centrality, aversion to wasting time, and, to a lesser extent, the valuation of hard work - are significant predictors of work-related obsession, compulsion, and excessive work involvement. Activity also emerged as a significant, though weaker, predictor of workaholism. Low agreeableness was found to be a weak predictor of workaholism. The results of the study show that high arousability, i.e., the ease of responding with emotional arousal, and beliefs that value work, such as viewing work as a value and a duty, are important in predicting levels of workaholism. High activity, understood as vigor and sociability, as well as low agreeableness, are weaker predictors of work addiction. Med Pr Work Health Saf. 2025;76(5).

The activity of serpins uses a specific mechanism, or process. This process comprises several steps and is related to significant structural changes that involve significant displacement of chain fragments and whole molecules of protease. An important role is played by a segment of the serpin chain called the Reactive Central Loop (RCL), which interacts with the protease by inhibiting its activity. For the covalent binding of the protease to serpin, the movement of the protease molecule is an effect of splicing the RCL segment into beta-sheet A of serpin. There are structural forms—native, latent, Michaelis complex, covalent, and cleaved—associated with serpin activity. In this work, all these structural forms are discussed using the fuzzy oil drop (FOD-M) model, where the assessment criterion of structuring is based on identifying the type of hydrophobicity distribution. The analysis reveals the specificity of the inhibition mechanism, including the specific action of the RCL. The structural changes involved in this process have been shown to preserve the distribution of hydrophobicity in the form preferred by the aqueous environment in which serpins are active. The disorder (according to FOD-M model) in two complexes (Michaelis and covalent) is treated as code for degradation factors.

Background: This survey of Polish employees replicates research on the relationship between narcissism, Machiavellianism and unethical pro-organisational behaviour (UPB) that was previously conducted in other countries such as China, Pakistan and the US. Positive associations between narcissism, Machiavellianism and UPB were expected to occur.Participants and procedure: The survey covered 250 people working in large corporations across Poland. The sample included 163 women (65%) and 87 men (35%). Narcissism was measured with the NARQ questionnaire, developed as an operationalisation of the narcissistic admiration and rivalry concept (NARC). The MACH-4 scale was used to measure Machiavellianism. Readiness for UPB, on the other hand, was measured using the Polish version of the UPB Scale.Results: The research showed statistically significant positive relationships between narcissistic admiration, rivalry and Machiavellianism and the readiness to engage in UPB. At the same time, narcissistic rivalry and its components aggressiveness and striving for supremacy, and Machiavellianism correlate most strongly with UPB. Regression and mediation analyses showed that the significant variables to predict higher levels of readiness to engage in UPB are rivalry (aggressiveness) and Machiavellianism. Machiavellianism, moreover, appears as a mediator in the positive relationship of rivalry and its components (devaluation of others, striving for supremacy) with UPB.Conclusions: Significant predictors of UPB are narcissistic rivalry, including aggressiveness, and Machiavellianism. A Machiavellian strategy may enable UPB to be undertaken by those with a tendency to dominate and devalue others.

Objectives: This study examined whether trust in supervisor, co-workers, and the organization mediates the relationship between organizational context and employee well-being. The research aimed to identify which components of trust have the strongest mediating effect, which organizational...

The contribution of the environment to protein folding seems obvious. The aqueous environment directs protein folding towards generating a centric hydrophobic core with a polar shell. The cell membrane environment—in which numerous proteins are anchored—to stabilise the arrangement, expects the exposure of hydrophobic residues and the concentration of polar residues in the central part—a channel for the transport of numerous molecules. The influence of these environments seems evident due to the persistent residence of proteins in their surroundings providing an external force field for structure stabilisation. Structural forms are also obtained with the participation of supporting proteins—such as proteins from the heat shock protein group—which accompany the folding process and temporarily provide an appropriate external force field in which the protein, having obtained the correct structure for its activity, is released from interaction with the supporting protein. This paper discusses an example of the contribution of Hsp104 to casein folding and the effect of disaggregase preventing inappropriate aggregation. For this purpose, a model called the fuzzy oil drop (FOD-M) was used, which takes hydrophobic interactions into account in the assessment of protein structure status. Their distribution in the protein body highlights the contribution and influence of the external force field—originating from Hsp104 and the disaggregase in this case.

The predisposition of amino acids towards accepting the appropriate secondary structure form is ambiguous. The identified sequences (6–12 aa in length – ChSeq data base) of the chameleon type (the same sequence accepting different secondary structures) constitute a puzzle that makes it difficult to indicate the initial conformation in a chain with a given amino acid sequence. The analysis of proteins presented in this paper uses the hydrophobicity distribution in protein body as the criterion for comaparable analysis of the status of helica/Beta-structural chameleon fragments in pairs of proteins. The sub-base is the object of analysis containg the proteins representing the organisation of hydrophobicity in one protein of the pair as ordered according to micelle-like organisation (hydrophobic core with polar surface) and the second one in pair with disordered hydrophobicity organisation. The status of chameleon sections appears to represent local organisation of hydrophobicity highly accordant in both proteins in chameleon pair independently on the status of the structural unit they belong to. The fuzzy oil drop model (FOD) in its modified form (FOD-M) is applied for analysis. This work aims to verify the hypothesis assuming the subordination of the form of secondary structure to the superior goal of obtaining a hydrophobicity distribution suitable for the given biological activity of the protein, ensuring biological functionality. Secondary structure is not an aim by itself. It is shown, that the main goal is to reach the structure representing specific activity. Secondary structure is a means to achieve this goal.