Nucleocapsid Annealing-Mediated Elektroforese (NAAM) Assay Hiermee kan de snelle identificatie van HIV-1 nucleocapsid Remmers

The overall goal of the experiment is the rapid identification of molecules able to inhibit the chaperone activities of HIV one nucleocapsid protein. In vitro NC is a small and highly basic protein with its structure characterized by a flexible and terminal domain and by two highly conserved zinc fingers that are engaged in interaction with viral nucleic acids. NC interacts with the tar RNA hairpin and its DNA complementary sequence CT A r and promotes the melting of their secondary structures to make them available for the ling of the tartar hybrid.

The protocol is performed by using the apical part of tar and sitar sequences when mixed together and incubated with nc. The hybrid is formed threading and circulators interacting with a oligonucleotides inhibit the NC catalyzed hybrid formation. The outcome of the reaction is analyzed by standard poly acrylamide, gel electrophoresis, TAR, and CA have different mobility in the gel compared to the hybrid.

Increasing concentrations of threading in inter collator leads to the decrease of the hybrid in parallel with the appearance of free tar and CT A.The main advantage of this technique over existing protocols, such as gel shift analysis or tar kneeling, is that it does not require preliminary manipulation of nucleic acids such as radioactive labeling. This method can Help answer key questions in the field of drug discovery such as HIV one and C inhibitors Generally individuals. New to this method, we struggle with the overall organization of a protocol, particularly with the serial dilution of each stock, the exact incubation time, and the correct procedure to stop the reaction.

To begin this procedure, prepare 10 microliters of one micromolar tar with oligonucleotide stock solution and 10 microliters of one micromolar CT A in TNMG one X buffer. Heat the tubes to about 95 degrees Celsius for five minutes, then cool them to room temperature in order for TAR and CT A to resm their stem bulge loop structures. To prepare one micromolar solution of hybrid tar CT A as control mix one microliter of 10 micromolar tar with one microliter of 10 micromolar CT A in TNMG one X buffer.

Fill the tube up with DEPC water to a total volume of 10 microliters. Then denature the oligonucleotides by heating the tube to 95 degrees Celsius for five minutes. Leave it to slowly cool to room temperature in order for tar to aneel to its complimentary sequence, CT A and to form the double stranded hybrid tar CT A.When all the solutions are cooled to room temperature, perform a short spin centrifugation, then add three microliters of GLB with SDS to each solution and vipe it inside the tube three times.

Place the samples on ice until the loading step. In this procedure, prepare 10 microliters of 500 micromolar, 250 micromolar, 50 micromolar, and five micromolar dilutions of compound one in milli Q water. Then prepare 27.5 microliters of four micromolar of tar and 27.5 microliters of four micromolar of CTA in TNMG one X buffer.

Heat the two tubes to about 95 degrees Celsius for five minutes in order to fold the structures and use 2.5 microliters of these folded oligonucleotide solutions for the following steps. Next, dilute the stock solution of both NC protein and NC 12 to 55 peptide in water to 80 micromolar. When the TAR and CAR solutions are cooled to room temperature, perform a short spin centrifugation of both tubes, then prepare 20 empty autoclaved tubes and place two rows of 10 tubes each in the rack for lab samples.

Afterward, add 2.5 microliters of the folded tar to every tube in the first row. Subsequently, add 2.5 microliters of the folded CT A to every tube. In the second row, add two microliters of the appropriate compound, one dilution to tar and CT A r.

Replace the compound with water in the samples for the analysis of NC and NC 12 to 55 peptide in the controls. Incubate the samples for 15 minutes at room temperature. After 15 minutes, mix the CT A R samples with the correspondent tar samples.

Add one microliter of 80 micromolar NC to the samples for NC analysis, or one microliter of 80 micromolar NC 12 to 55 peptide to the samples for NC 12 to 55 peptide analysis. After another 15 minutes of incubation at room temperature, stop the reaction by adding three microliters of GLB with SDS to each sample. Pipette the mixture in each tube three times and then place it on ice.

Repeat this step using the samples for NC and NC 12 to 55 peptide analysis and keep the samples on ice until the loading step. Now, remove the lid of the gel apparatus. Load 13 microliters of each sample into the wells.

Replace the lid of the gel apparatus before turning it on. Run the gel for two hours and 30 minutes at 200 constant volts until the dye has migrated to 1.5 centimeters above the bottom of the gel. Afterward, place the gel in a suitable container with a desired nucleic acid staining solution for 30 to 45 minutes with stirring sub.

Put the gel on a transluminator imaging system to detect the nucleic acids by the fluorescent signal. The name assay is used to assess the ability of threading and inter collators to stabilize dynamic nucleic acid structures and inhibit NC chaperone activity. Threading inter collators are plainer aromatic molecules substituted by bulky side chains located at the opposite sides of the ring system, such as the anthraquinone shown here.

This figure shows the outcome of the name assay in the presence of compound one, a known threading inter collator in the presence of full length NC or of the truncated peptide. In both cases, the formation of the tar ct, a hybrid by NC, is reduced by increasing the concentration of the inter collator. At the same time the amount of free tar and CT A R increases.

While attempting this procedure, it's important to remember to use JA loading buffer with SDS. That is a critical step for the optimal success of name. Say, if this step is not followed, it is not possible to distinguish nucleic acid bands in the gel system.

After watching this video, you should have a good understanding of how to perform an MSA to any letter room temperature oligonucleotides folded in inable airplane structures, and how to analyze the outcome of the reaction, employ either the recombinant full length NC protein or a truncated synthetic NC peptide to identify trading interpolators Inhibiting nc. Don't forget that working with intercos and poly acrylamide can be extremely dangerous and taking precautions such as wearing lab coat gloves, and safety glasses should always be taken while performing this protocol.