Rabbit anti-Hexahistidine Polyclonal antibody, FITC-Conjugated

Aggregation of amyloid beta peptide (A beta) is closely associated with the occurrence and development of Alzheimer's disease (AD). Reproducible and detailed studies on the aggregation kinetics and structure of various aggregates have been conducted using recombinant A beta peptides. While the His(6)-tag is commonly used in the purification of recombinant proteins due to its great simplicity and affinity, there is little information on the aggregation of His(6)-tagged A beta and its corresponding cytotoxicity. Moreover, it is also unclear whether there is an effect of the His6-tag on the amyloidogenicity and cytotoxicity of recombinant A beta(1-42). Herein, a method to express and purify a mutant C-terminally His(6)-tagged A beta(1-42) (named as A beta(1-42)-His(6)) from Escherichia coli was described. A beta(1-42)-His(6) aggregated into beta-sheet-rich fibrils as shown by thioflavin T fluorescence, atomic force microscopy and circular dichroism spectroscopy. Moreover, the fibrillar recombinant A beta(1-42)-His(6) showed strong toxicity toward PC12 cells in vitro. Molecular dynamics simulations revealed that the His6-tag contributed little to the secondary structure and intermolecular interactions, including hydrophobic interactions, salt bridges, and hydrogen bonding of the fibrillar pentamer of A beta(1-42). This highlights the biological importance of modification on the molecular structure of A beta. Thus, the easily purified high-quality A beta(1-42)-His(6) offers great advantages for screening aggregation inhibitors or in vitro confirmation of rationally designed drugs for the treatment of AD.

The research was carried out with the purpose of evaluating the production and protein value of edible fungi using agricultural and forest residues (cornhusk, wheat stubble, barley, eucalyptus sawdust among others) generated in rural communities of the Cusco region. The crop cycle (CC), Biological Efficiency (EB) and Production Rate (TP) were determined. Pleurotus ostreatus showed greater adaptability to the different environmental parameters in the three communities with EB that ranged between 43.8-58.2%, CC between 42-91 days and TP between 0.6 and 1.4%, while P. djamor and Lentinula edodes only presented fruiting bodies in the communities of Harin and San Nicolas de Bari with EB: 27.3-34.8%, CC: 42-90 days and TP: 0.4-0.7% for P. djamor, and EB: 40.6-51.3%, CC: 135-155 days and TP: 0.3-0.4% for L. edodes. The dry weight protein analysis yielded considerable results for P. ostreatus (35.45%) and L. edodes (34.54%) while P. djamor presented 19.68%. According to the Pico Tag Water system, P. ostreatus has eight of the ten essential amino acids required for healthy eating (His, Thr, Val, Met, Ile, Leu, Phe and Lys). The three species are an important source of phosphorus (366.6 mg/100 g), magnesium (54 mg/100 g), calcium (16.7 mg/100 g) and iron (3.6 mg/100 g), average values that exceed reported in cow's milk, chicken liver, and white corn.