We present a computational and experimental study on the folding and aggregation in solutions of multiple protein mixtures at different concentrations. We show how in protein mixtures, each component is capable of maintaining its folded state at desensitises higher then the one at which they would precipitate in single species solutions. We demonstrate the generality of our observation over many different proteins using computer simulations capable of fully characterising the cross-aggregation phase diagram of all the mixtures. Dynamic light Scattering experiments were performed to evaluate the aggregation of two proteins, the bovine serum albumin (BSA) and the consensus tetratricopeptide repeat (CTPR), in solutions of one or both proteins. The experiment confirm our hypothesis and the simulations. These findings elucidate critical aspects on the cross-regulation of expression and aggregation of proteins exerted by the cell and on the evolutionary selection of folding and not-aggregating protein sequences, paving the way for new experimental tests.

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An electrochemical biosensing platform for serum autoantibodies (AAbs) detection is reported in this work, exploiting for the first time six Alzheimer's disease (AD)-specific phage-derived and frameshift aberrant HaloTag peptides as receptors, immobilized on magnetic microbeads (MBs) surface and captured on disposable electrodes to perform amperometric detection. Operational analytical characteristics and clinical diagnostic ability of the bioplatform were probed in optimized key experimental conditions by analysing serum AAbs of AD patients and healthy subjects. The value of 100 % obtained for AUC, sensitivity, and selectivity from the all peptides combined ROC curve, indicate full AD-diagnostic capability of the methodology, which was further implemented, as proof of concept, in a POC multiplexing platform to detect the signature in a single test over clinically actionable times (1 h 15 min), opening great promise for the type of diagnosis and AD patients' monitoring follow-up currently pursued.Alzheimer's disease (AD) is the most common form of dementia in elderly age groups worldwide, with an estimated prevalence of 10-30 % and an average duration of about 10 years since the first clinical symptoms. [1,2] However, AD has long preclinical and prodromal stages which extend the disease for up to 20 years.