Let's chat! Integrating ChatGPT in medical student assignments to enhance critical analysis.

Advances in artificial intelligence (AI) are overtaking the progress in teaching and assessment. Traditional assignments, such as written reports and posters, have become obsolete as these can be created almost entirely using AI tools. As educators, it is imperative that we devise out-of-the-box assignments to give students the opportunity to demonstrate their understanding, ability to synthesize and think critically, while promoting the ethical and innovative use of AI.

Novel homozygous PANK2 mutation causing atypical pantothenate kinase-associated neurodegeneration (PKAN) in a Cypriot family.

Pantothenate kinase-associated neurodegeneration (PKAN) is the commonest, recessively inherited form of neurodegeneration with brain iron accumulation (NBIA) resulting from mutations in the pantothenate kinase 2 (PANK2) gene on chromosome 20. PKAN is usually rapidly progressive, presenting in the vast majority in the first decade of life (classic form). A rarer, later onset and slowly progressive (atypical) PKAN form also exists.

Investigating models of protein function and allostery with a widespread mutational analysis of a light-activated protein.

To investigate the relationship between a protein's sequence and its biophysical properties, we studied the effects of more than 100 mutations in Avena sativa light-oxygen-voltage domain 2, a model protein of the Per-Arnt-Sim family. The A. sativa light-oxygen-voltage domain 2 undergoes a photocycle with a conformational change involving the unfolding of the terminal helices.

The amino-terminal helix modulates light-activated conformational changes in AsLOV2.

The mechanism of light-triggered conformational change and signaling in light-oxygen-voltage (LOV) domains remains elusive in spite of extensive investigation and their use in optogenetic studies. The LOV2 domain of Avenasativa phototropin 1 (AsLOV2), a member of the Per-Arnt-Sim (PAS) family, contains a flavin mononucleotide chromophore that forms a covalent bond with a cysteine upon illumination. This event leads to the release of the carboxy-terminal Jα helix, the biological output signal.

TULIPs: tunable, light-controlled interacting protein tags for cell biology.

Naturally photoswitchable proteins offer a means of directly manipulating the formation of protein complexes that drive a diversity of cellular processes. We developed tunable light-inducible dimerization tags (TULIPs) based on a synthetic interaction between the LOV2 domain of Avena sativa phototropin 1 (AsLOV2) and an engineered PDZ domain (ePDZ). TULIPs can recruit proteins to diverse structures in living yeast and mammalian cells, either globally or with precise spatial control using a steerable laser.

Dinitrosyliron complexes are the most abundant nitric oxide-derived cellular adduct: biological parameters of assembly and disappearance.

It is well established that nitric oxide ((•)NO) reacts with cellular iron and thiols to form dinitrosyliron complexes (DNIC). Little is known, however, regarding their formation and biological fate. Our quantitative measurements reveal that cellular concentrations of DNIC are proportionally the largest of all (•)NO-derived adducts (900 pmol/mg protein, or 45-90 μM).

Apparent structural differences at the tetramerization region of erythroid and nonerythroid beta spectrin as discriminated by phage displayed scFvs.

We have screened a human immunoglobulin single-chain variable fragment (scFv) phage library against the C-terminal tetramerization regions of erythroid and nonerythroid beta spectrin (βI-C1 and βII-C1, respectively) to explore the structural uniqueness of erythroid and nonerythroid β-spectrin isoforms. We have identified interacting scFvs, with clones "G5" and "A2" binding only to βI-C1, and clone "F11" binding only to βII-C1. The K(d) values, estimated by competitive enzyme-linked immunosorbent assay, of these scFvs with their target spectrin proteins were 0.

Inhibition of calpain but not caspase activity by spectrin fragments.

Calpains and caspases are ubiquitous cysteine proteases that are associated with a variety of cellular pathways. Calpains are involved in processes such as long term potentiation, cell motility and apoptosis, and have been shown to cleave non-erythroid (brain) alpha- and beta-spectrin and erythroid beta-spectrin. The cleavage of erythroid alpha-spectrin by calpain has not been reported.

Association studies of erythroid alpha-spectrin at the tetramerization site.

The functional roles of residues 21-43 and 55-59 in the alpha-spectrin N-terminal region in forming tetramers were determined by the introduction of mutations at each of these positions. We measured association affinities for tetramer formation (K(d)), which can be used to predict clinical severity, of these mutants. A total of nine residues critical for association with beta-spectrin were found.

Conformational changes at the tetramerization site of erythroid alpha-spectrin upon binding beta-spectrin: a spin label EPR study.

We used cysteine scanning, isothermal titration calorimetry (ITC) and spin label EPR methods to study the two regions that flank the partial domain Helix C' of the N-terminal end of alpha-spectrin (residues 14-20 and residues 44-54) in the absence and presence of a model protein of the beta-spectrin C-terminal end. In the absence of beta-spectrin, residues 14-20 and 46-52 were known to be unstructured. The EPR spectral values of the inverse line width (Delta H (-1)) and of the width between the low field peak and the central peak ( aZ) of residues in part of the first unstructured region (residues 17-20) and of most residues in the second unstructured junction region (residues 46-52) changed dramatically upon association with beta-spectrin, suggesting that the two regions undergo a conformational change, becoming more rigid and likely becoming helical.

Potential artifacts in using a glutathione S-transferase fusion protein system and spin labeling electron paramagnetic resonance methods to study protein-protein interactions.

Site-directed spin labeling electron paramagnetic resonance methods have been an important tool in studying protein-protein interactions. Labels are often attached to a cysteine residue, and spectra are acquired with and without binding partner(s) to provide information on the binding. This requires a knowledge of the label location which is simplified if the label remains faithfully attached to the designated residue in the complex.