| Product Description | Aladdin's WELQ Protease specifically recognizes the tetrapeptide sequence Trp-Glu-Leu-Gln (WELQ) and cleaves the peptide bond after Gln (Q), which is commonly used to remove N-terminal His or other tags from recombinant proteins, with the most prominent advantage that the N-terminus of the target protein does not leave any additional amino acid residues after cleavage. WELQ protease is a serine protease-like proteins derived from Staphylococcus aureus [1,2]. It works in a relatively wide temperature range (4-30℃) and pH range (6.5-9.0) and does not require special reaction buffers for its reaction.This WELQ protease with His-tag is particularly suitable for on-column cleavage of His-tagged target proteins. After cleavage, the cleaved His-tag and WELQ protease bind to the His-tag Purification Resin while the target protein with His-tag removed is eluted, which greatly facilitates the purification of target proteins. Alternatively, the WELQ protease and the tag removed from target proteins can also be removed using a nickel column and a purification column for corresponding tags, respectively.Please refer to Figure 1 for the performance of this product. Figure 1. Digestion of GST-tagged proteins using Aladdin's WELQ Protease and a competitor. Fifty micrograms of fusion protein containing the WELQ Protease recognition site (36kD) were incubated with 1 U and 2 U of WELQ Protease in 50mM Tris-HCl (pH 8.0) buffer, respectively, at 4℃ and 25℃. Samples were taken after different time courses as indicated in the figure and subjected to SDS-PAGE electrophoresis, followed by Coomassie Brilliant Blue staining. The digestion products were the target protein of ~10kD and the GST tag of ~26kD. As shown in the figure, this product has comparable enzyme activity to a widely received Competitor. This figure is for reference only, which may vary due to different experimental conditions. This WELQ Protease has a molecular weight of approximately 22kDa and a purity of ≥95%. It is free of DNA endonuclease and exonuclease, RNAase and phosphodiesterase.Unit definition
Precautions： Enzyme activity of WELQ Protease can be partially inhibited by 2M urea or 0.25M guanidine hydrochloride.This product is for R&D only. Not for drug, household, or other uses.For your safety and health, please wear a lab coat and disposable gloves during the operation.
Instructions for Use： 1.Optimization of digestion conditions: The exposure extent of the WELQ Protease recognition site, the amino acid sequence near the site and the degree of protein aggregation all affect the digestion effect of WELQ Protease. Thus, it is recommended to optimize the digestion conditions for different proteins from three aspects, reaction temperature (4-30℃), reaction time (1-12h or overnight), and enzyme amount (1:5-1:100 U/μg).a.Set up the reaction as follows: Component Amount Substrate Protein 50μg WELQ Protease (5U/μl)* 0.5/1/2/10U Reaction Buffer** To 50μl * Set the ratio of enzyme to substrate protein to 1:100, 1:50, 1:25, and 1:5 (U/μg), respectively. Except the 1:5 ratio, we recommend diluting WELQ Protease to 0.5 U/μl before use.** We recommend using 10-100 mM Tris-HCl (pH 8.0) as Reaction Buffer. b.Incubate the reaction mix at 15-30℃. After 1, 3, 6 and 12 hours (or overnight) of reaction, respectively, take 10μl of the reaction product for SDS-PAGE analysis. When the reaction time is longer than 16 hours, we recommend incubation at temperature below 20℃.c.After the optimal reaction condition has been determined, the reaction can be scaled up. For on-column digestion, the required enzyme amount needs to be further optimized.2.Enzyme digestion in solution and purificationa.We recommend using 10-100mM Tris-HCl (pH8.0), 10-100mM Na3PO4 (pH7.4), or 10-20mM K3PO4 (pH7.4) as Reaction Buffer.Note: If affinity chromatography is to be performed subsequently, the Reaction Buffer can contain 50mM NaCl and 5-20mM Imidazole.b.Add WELQ Protease and incubate at 15-30℃. Note: If the protein is unstable or the digestion reaction takes longer than 16 hours, incubate the reaction at 4-20℃.c.Add the reaction product to the His-tag Purification Resin ( His-tag Purification Resin10ml P2218 His-tag Purification Resin100ml P2220 His-tag Purification Resin1000ml P2226 His-tag Protein Purification Kit10ml P2229S His-tag Protein Purification Kit10ml P2233-10ml His-tag Purification Resin10ml P2233-100ml His-tag Purification Resin100ml P2233-1000ml His-tag Purification Resin1000ml P2302 PreScission Protease 100U P2303 PreScission Protease 500U P2307 TEV Protease (His-tag) 1000U P2308 TEV Protease (His-tag) 10000U P2310S TEV Protease 1000U P2310M TEV Protease 10000U P2312S SUMO Protease 200U P2312M SUMO Protease 1000U P2312L SUMO Protease 5000U
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