PNGase F can remove virtually all types ofN-linked glycans6,7

PNGase F can remove virtually all types ofN-linked glycans6,7. in pet cells but differ in lower microorganisms1. The comprehensive evaluation from the glycosylation of protein is normally a field unto itself and needs extensive assets and expertise to execute properly. However a variety of available enzymes that remove sugars (glycosidases) makes possible to have a general idea of the glycosylation status of a protein in a standard laboratory setting. Here we illustrate the use of glycosidases for the analysis of a model glycoprotein: recombinant human chorionic gonadotropin beta (hCG), which carries twoN-glycans and fourO-glycans5. The technique requires only simple instrumentation and common consumables, and it can be readily adapted to the analysis of multiple glycoprotein samples. Several enzymes can be used in parallel to study a glycoprotein. PNGase F is able to remove almost all types ofN-linked glycans6,7. ForO-glycans, there is no available enzyme that can cleave an intact oligosaccharide from the protein backbone. Instead,O-glycans are trimmed by exoglycosidases to a short core, which is usually then easily removed byO-Glycosidase. The Protein Deglycosylation Mix contains Arctiin PNGase F,O-Glycosidase, Neuraminidase (sialidase), 1-4 Galactosidase, and -N-Acetylglucosaminidase. It is used to simultaneously removeN-glycans and someO-glycans8. Finally, the Deglycosylation Mix was supplemented with a mixture of other exoglycosidases (-N-Acetylgalactosaminidase, 1-2 Fucosidase, 1-3,6 Galactosidase, and 1-3 Galactosidase ), which help remove otherwise resistant monosaccharides that could be present in certainO-glycans. SDS-PAGE/Coomasie blue is used to visualize differences in protein migration before and after glycosidase treatment. In addition, a sugar-specific staining method, ProQ Emerald-300, shows diminished signal as glycans are successively removed. This protocol is designed for the analysis of small amounts of glycoprotein (0.5 to 2 g), although enzymatic deglycosylation can be scaled NSD2 up to accommodate larger quantities of protein as needed. Keywords:Molecular Biology , Issue 58, Glycoprotein, N-glycan, O-glycan, PNGase F, O-glycosidase, deglycosylation, glycosidase Download video stream. == Protocol == == 1. Enzymatic deglycosylation == Use PCR tubes to minimize water loss due to evaporation. Label one set of tubes 1 to 7. Thaw the 10X G7 buffer, the 10X glycoprotein denaturing buffer, and the 10% NP-40 and gently tap the tubes to mix the contents. Keep at room heat. Place the enzyme-containing vials on ice. Try to minimize thaw/freeze cycles. Dissolve the contents of the hCG vial (150 g) in 600 l of dH2O and keep on ice. Prepare 1 ml of 1X G7 buffer by diluting the 10X stock in dH2O. Dilute 0.5 l of PNGase F in 25 l 1X G7 buffer and keep on ice. Prepare the exoglycosidase mix (EG mix) by combining Arctiin 2 Arctiin l each of -N-Acetylgalactosaminidase, 1-2 Fucosidase, 1-3 Galactosidase, and 1-3, 6 Galactosidase. Set up PCR tubes as indicated: Cap the tubes, mix gently and place in the thermocycler, close the lid and denature the proteins by incubating 10 minutes at 94C, followed by a 4C hold (using PCR tubes in a thermocycler greatly prevents evaporation in small volume samples). Remove the tubes from thermocycler and centrifuge to remove any visible condensation. Add the following reagents as indicated: Close the PCR tubes using new caps (discard the used ones since they do not fit properly after one incubation cycle). Mix the tubes by gently tapping 4 occasions and then spin the contents down. Place the tubes in the thermocycler and incubate at 37 C for 4 hours then cool the samples to 4 C. == 2. SDS-PAGE of deglycosylated samples == Prepare 130 l fresh 3X reducing SDS loading buffer by adding 4 l of 1 1.25M DTT. Add 12.5 l of the prepared 3X reducing SDS loading buffer to each sample. Close the tubes with new caps and gently tap the tubes to mix. Incubate the tubes in a thermocycler at 94C for 5 minutes and then cool to 4 C. Load 30 l of each sample and 10 l of the protein marker on a 10-20% Tris-Glycine gel. Save the remainder of the sample for part 3.1. Load 10l of ColorPlus Prestained Protein Marker. Electrophorese the gel at 130 volts at room temperature until the dye front is usually near the bottom of the gel. When the gel has finished running, remove the gel from the cast and.