sigma现货代理Dispase II D-4693Related CategoriesApplication Index, Biochemicals and Reagents, Cell Biology, Dissociation, Enzymes, Inhibitors, and Substrates,More…activity ≥0.5 units/mg solidsol
详细介绍
sigma现货代理Dispase II D-4693
Description
Analysis Note
The enzyme can be initially dissolved in 50 mM Hepes/KOH pH 7.4, 150 mM NaCl at 10 mg/ml. Further dilutions should be made in the cell culture media most appropriate for the cells being dissociated. Dispase is a metalloproteinase and is activated by divalent cations including Ca2+ , Mg2+, Mn2+ and Fe2+.
Preparation Note
A 50 U/mL stock solution may be prepared by dissolving the powder in a buffer containing 10 mM NaAc (pH 7.5) and 5 mM CaAc. It should be stored at 4 °C.
Unit Definition
One unit will hydrolyze casein to produce color equivalent to 1.0 μmole (181 μg) of tyrosine per min at pH 7.5 at 37 °C (color by Folin-Ciocalteu reagent), unless otherwise indicated.
Physical form
lyophilized powder containing calcium acetate and milk sugar
Application
The enzyme from Sigma has been used in developing a protocol for ex vivoculture of mouse embryonic mammary buds.[5] It has been used in the treatment of rat heart pieces during the isolation of mitochondria from rat heart.[6] It has also been used for the isolation of dental pulp stem cells (DPSCs) by enzymatic hydrolysis. These cells have been compared with DPSCs isolated by explant method to analyse their stem cell and differentiation properties.[1] Dispase II has been used for Fluorescence-Activated Cell Sorting (FACS).[3] It has also been used for separating visceral yolk sac layers.[2]
Biochem/physiol Actions
Dispase II is a neutral protease that hydrolyzes the N-terminal peptide bonds of non-polar amino acid residues. It may be used for separating many tissues and cells grown in vitro. The enzyme is very gentle and does not damage cell membranes. It can also be used to prevent clumping in suspension cultures. This protease cleaves fibronectin and type IV collagen, but not laminin, type V collagen, serum albumin, or transferrin.[4] Dispase II is specific for the cleavage of Leucine-Phenylalanine bonds. Ca2+, Mg2+, Mn2+, Fe2+, Fe3+ and Al3+activate the enzyme. EDTA, EGTA, Hg2+ and other heavy metals inhibit the enzyme activity.[7] The enzyme contains 1g-atom of zinc per g-mol of purified enzyme. If this zinc component is removed by chelating agents such as EDTA or EGTA, an inactive apoenzyme is obtained. The enzyme is not inhibited by serum.
QIAexpress Ni-NTA Protein Purification System基于获得的Ni-NTA（氨基三乙酸镍）树脂，对含有6个或以上组氨酸残基（连续或交替）亲合标签的蛋白选择能力强。该技术可在天然或变性条件下，从所有表达体系中一步纯化几乎所有的His-tagged蛋白。NTA含有四个镍离子螯合位点，与镍的结合能力比其他仅有三个金属螯合位点的金属螯合纯化方法的结合能力强。多出的一个螯合位点可防止镍离子脱落，因此具有更强的结合能力，蛋白纯度比金属螯合纯化方法的蛋白纯度高。QIAexpress技术可用于从杆状病毒、哺乳动物细胞、酵母和细菌等各种表达体系中纯化His-tagged蛋白。
Procedure
His-tagged蛋白的纯化包括四个步骤：裂解、结合、洗涤和洗脱（参见Protein purification with the Ni-NTA protein purification system）。使用QIAexpress 技术纯化重组蛋白无需依赖于蛋白的三维结构或6xHis标签。因此可实现在天然或变性条件下，从稀释溶液或细胞裂解液中一步纯化蛋白。可使用强变性剂和洗涤剂高效溶解和纯化受体、膜蛋白和形成包涵体的蛋白。洗涤缓冲液中可包含有能高效去除非特异性结合产物的试剂（见表）。在温和条件下加入100–250 mM咪唑作为竞争性洗脱试剂或降低pH值，可洗脱得到纯化蛋白。
