UV Detection and Avoidance of Protein in Basella alba leaf Mucilage Polysaccharide by differential precipitation

Objective: In the aim of refining mucilage polysaccharide extracted from the leaf of Basella alba, extraction and differential precipitation of the protein content was studied. This was attempted by pH adjustment by adding Trichloroacetic acid (TCA) and Hydrochloric acid (HCl). Materials and Methods: The presence of residual protein before and after deproteinization in the polysaccharide solution was detected by UV spectrum analysis. The % polysaccharide, % polysaccharide loss, protein concentration and the deproteinization efficiency were studied as comparative indices to evaluate the precipitation experimental conditions using pH adjustment. Results: The result showed that 10% w/v TCA precipitated over 80% of the protein when the pH of the aqueous polysaccharide solution was 3. Discussion: TCA was proved to be superior to hydrochloric acid as evidenced by the highest deproteinization efficiency (83.3%). The polysaccharides of all the extracted solutions obtained were identified with only slight variations in percentage. The Hcl method excelled over the TCA method in obtaining polysaccharides with little lower percentage of polysaccharide loss (13.94 %). Conclusion: The TCA method will offer a room for deproteinization of polysaccharides if optimization is studied.

Effect of Cod Residual Protein Supplementation on Markers of Glucose Regulation in Lean Adults: A Randomized Double-Blind Study

Large quantities of protein-rich cod residuals, which are currently discarded, could be utilized for human consumption. Although fish fillet intake is related to beneficial health effects, little is known about the potential health effects of consuming cod residual protein powder. Fifty lean adults were randomized to consume capsules with 8.1 g/day of cod residual protein (Cod-RP) or placebo capsules (Control group) for eight weeks, in this randomized, double-blind study. The intervention was completed by 40 participants. Fasting glucose and insulin concentrations were unaffected by Cod-RP supplementation, whereas plasma concentrations of α-hydroxybutyrate, β-hydroxybutyrate and acetoacetate all were decreased compared with the Control group. Trimethylamine N-oxide concentration in plasma and urine were increased in the Cod-RP group compared with the Control group. To conclude, the reduction in these potential early markers of impaired glucose metabolism following Cod-RP supplementation may indicate beneficial glucoregulatory effects of cod residual proteins. Trimethylamine N-oxide appears to be an appropriate biomarker of cod residual protein intake in lean adults.

Lipid specificity of the immune effector perforin

Perforin is a pore forming protein used by cytotoxic T lymphocytes to remove cancerous or virus-infected cells during immune response. During the response, the lymphocyte membrane becomes refractory to perforin function by accumulating densely ordered lipid rafts and externalizing negatively charged lipid species. The dense membrane packing lowers the capacity of perforin to bind, and negatively charged lipids scavenge any residual protein before pore formation. Using atomic force microscopy on model membrane systems, we here provide insight into the molecular basis of perforin lipid specificity.

Effect of Modified Eggshell on Adsorption Capacity of Chromium(VI) from Aqueous Solution

The aim of this work is to investigate the use of eggshell for adsorption of Cr(VI) from aqueous solution and the effect of thermal treatment as well as coating with Fe2O3 of eggshell on the extraction percent of Cr(VI). The XRD, FTIR and SEM techniques proved that the eggshell mainly composed of calcite rhombohedral structure in addition to a trace of quartz silica residual protein fibers. Heating at 550 ºC does not decompose eggshell but decomposes the residual protein. The effect of pH, weight of eggshell adsorbent, contact time, and initial concentration of Cr(VI) ions on the adsorption of Cr(VI) on eggshell sorbents were determined under static conditions by the batch equilibrium technique. The sorption kinetic as well as mechanistic isotherm parameters of Cr(VI) on the eggshell sorbent, were analyzed. It was concluded that the adsorption of Cr(VI) on eggshell increases as pH increases in the range 3-7, then, with decreases at higher pH. The extraction percent of Cr(VI) increases with an increase in the dosage of eggshell sorbents. The optimum dosage of eggshell adsorbents was found to be 5 g after which the extraction percent of Cr(VI) did not marked increase. The extraction percent of Cr(VI) by eggshell sorbents rapidly increases within 60 min followed by a slower extraction after that when maximum adsorption was reported. The adsorption capacity of Cr(VI) ions is slightly reduced in case of heated eggshell due to the change that occurs in the pore size distribution and structure of eggshell during heating. Hence, the thermal treatment and coating with Fe2O3 do not affect the chemical structure of eggshell sorbents. The adsorption kinetics data were best fitted with the pseudo-second-order equation and the adsorption isotherms were best fitted with the Langmuir isotherm model.

Biological Plasticity Rescues Target Activity in CRISPR Knockouts

Gene knockouts (KOs) are efficiently engineered through CRISPR-Cas9-induced frameshift mutations. While DNA editing efficiency is readily verified by DNA sequencing, a systematic understanding of the efficiency of protein elimination has been lacking. Here, we devised an experimental strategy combining RNA-seq and triple-stage mass spectrometry (SPS-MS3) to characterize 193 genetically verified deletions targeting 136 distinct genes generated by CRISPR-induced frameshifts in HAP1 cells. We observed residual protein expression for about one third of the quantified targets, at variable levels from low to original, and identified two causal mechanisms, translation reinitiation leading to N-terminally truncated target proteins, or skipping of the edited exon leading to protein isoforms with internal sequence deletions. Detailed analysis of three truncated targets, BRD4, DNMT1 and NGLY1, revealed partial preservation of protein function. Our results imply that systematic characterization of residual protein expression or function in CRISPR-Cas9 generated KO lines is necessary for phenotype interpretation.