| Description | The enzyme is useful for the determination of α-amylase and inorganic phosphate in clinical analysis.PROPERTIESMolecular weight: ca. 34 kDa (gel filtration)Structure: monomer of ca. 25 kDa (SDS-PAGE)Michaelis constant: 2.3×10^−4 M (β-d-glucose-1-phosphate)pH Optimum: ca. 7.0 (The enzyme is useful for the determination of α-amylase and inorganic phosphate in clinical analysis.PROPERTIESMolecular weight: ca. 34 kDa (gel filtration)Structure: monomer of ca. 25 kDa (SDS-PAGE)Michaelis constant: 2.3×10^−4 M (β-d-glucose-1-phosphate)pH Optimum: ca. 7.0 (Fig. 1)pH Stability: 5.0–9.5 (Fig. 2)Optimum temperature: 40°C (Fig. 3)Thermal stability: below 45°C (Fig. 4)Stability (liquid form): stable at 37°C for at least one week (Fig. 5)Stability (powder form): stable at 30°C for at lest one month (Fig. 6)Activators: Mg2+, Mn2+, Co2+, Ni2+Inhibitors: Hg2+, Zn2+, Cu2+, Cd2+STABILIZERS: lactose, EDTAASSAY PROCEDURE PrincipleThe appearance of NADPH is measured spectrophotometrically at 340 nm.ReagentsA. HEPES–NaOH buffer, 0.3 M; pH 7.0, containing 40 mM KCl, 4 mM MgCl2 and 1.6% (w/v) Triton X-100: dissolve 7.15 g of HEPES, 298 mg of KCl, 81.3 mg of MgCl2·6H2O and 1.6 g of Triton X-100 in 75 ml of distilled water, adjust to pH 7.0 with 4 N NaOH and dilute with distilled water to 100 ml.B. d-Glucose-1,6-bisphosphate (G-1,6-P2) solution, 3.0 mM : 60.7 mg of G-1,6-P2 cyclohexylammonium·4H2O/ 25 ml of distilled water.C. NADP+ solution, 12 mM: 230 mg of NADP+·Na/25 ml of distilled water.D. β-d-Glucose-1-phosphate (β-G-1-P) solution, 22 mM:167 mg of β-G-1-P disodium salt/25 ml of distilled water.E. Glucose-6-phosphate dehydrogenase (G6PDH) solution: 1750 U/ml.F. Enzyme dilution buffer: mix 10 mM KH2PO4 solution and 10 mM K2HPO4 solution to make a pH 7.0 solution.Sample: dissolve the lyophilized enzyme to a volume activity of 1.0–3.0 U/ml with ice-cold enzyme dilution buffer (Reagent F) immediately before measurement. Procedure1. Pipette the following reagents into a cuvette (light path: 1 cm).1.5 ml HEPES–NaOH buffer (Reagent A)0.3 ml G-1,6-P2 solution (Reagent B)0.3 ml NADP+ solution (Reagent C)0.3 ml β-G-1-P solution (Reagent D) 0.02 ml G6PDH solution (Reagent E)0.6 ml Distilled water2. Equilibrate at 37°C for about 5 min.3. Add 0.03 ml of sample and mix.4. Record the increase of absorbance at 340 nm in a spectrophotometer thermostated at 37°C, and calculate the ∆Aper min using the linear portion of the curve (∆AS).The blank solution is prepared by adding enzyme dilution buffer (Reagent F) instead of sample (∆A0).CalculationActivity can be calculated by using the following formula:6.2: Millimolar extinction coefficient of NADPH at 340 nm (cm2/µmol)df: Dilution factorC: Content of β-phosphoglucomutase preparation in sample (mg/ml)APPLICATIONSThe enzyme is useful for the determination of α-amylase and inorganic phosphate in clinical analysis.EXPERIMENTAL DATA... Read More | Inquire | Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard Purity: >95%, by SDS-PAGE visualized with Coomassie® Blue Staining. Description： CD4, also known as L3T4, T4, and W3/25, is an approximately 55 kDa type I transmembrane glycoprotein that is expressed predominantly on thymocytes and a subset of mature T lymphocytes. It is a standard phenotype marker for the identification of T cell populations. Mature human CD4 consists of a 371 amino acid (aa) extracellular region containing four immunoglobulin-like domains, a 22 aa transmembrane segment, and a 40 aa cytoplasmic domain. Within the ECD, human CD4 shares approximately 52% aa sequence identity with mouse and rat CD4. CD4 is expressed along with CD8 on double positive T cells during their development in the thymus. Either CD4 or CD8 expression is then lost, giving rise to single positive (SP) CD4+ or CD8+ mature T cells. CD4+ SP cells, also known as T helper cells, further differentiate into multiple subsets of CD4+ cells including Th1, Th2, Th17, Tfh, and Treg cells which regulate humoral and cellular immunity. CD4 is reexpressed on circulating CD8+ T cells upon activation and contributes to their cytotoxic effector activity. In human, CD4 is additionally expressed on macrophages, neutrophils, monocytes, NK cells, and neurons and glial cells in the brain. Similar CD4 distribution between species cannot be assumed as demonstrated by its presence on macrophages in human and rat but not in mouse. CD4 binds directly to MHC class II molecules on antigen presenting cells. This interaction contributes to the formation of the immunological synapse which is focused around the TCR-MHC class II-antigenic peptide interaction. Palmitoylation of two cysteine residues in the cytoplasmic tail of CD4 promotes the localization of CD4 in lipid rafts and its ability to augment TCR signaling via activation of the tyrosine kinase Lck. CD4 also functions as a chemotactic receptor for IL-16 and, in human, as a co-receptor for the gp120 surface glycoprotein of HIV-1... Read More | Purity>90% SDS-PAGE.Background:Luteinizing Hormone (LH) is a 42 kDa heterodimer belonging to the glycoprotein hormone family. It is composed of noncovalently linked glycosylated alpha and beta chains. The alpha subunit (CG alpha ) is also a component of Follicle-Stimulating Hormone (FSH), ThyroidPurity>90% SDS-PAGE.Background:Luteinizing Hormone (LH) is a 42 kDa heterodimer belonging to the glycoprotein hormone family. It is composed of noncovalently linked glycosylated alpha and beta chains. The alpha subunit (CG alpha ) is also a component of Follicle-Stimulating Hormone (FSH), Thyroid-Stimulating Hormone, and Chorionic Gonadotropin. The unique beta subunit confers the protein’s specific biological action and is responsible for the interaction with its receptor. The approximately 20 kDa human CG alpha subunit shares 73% and 72% amino acid (aa) sequence identity with the mouse and rat orthologs, respectively. The approximately 18 kDa human LH beta subunit shares 71% and 72% aa sequence identity with the mouse and rat orthologs, respectively. Multiple isoforms of LH exist due to differences in the post-translational glycosylation, sialylation, and sulphation modifications of its subunits. The composition, longevity, and activity of the different LH isoforms vary throughout a woman’s menstrual cycle and reproductive life cycle. LH is produced and secreted by the anterior pituitary gland. Its secretion is controlled by Gonadotropin-Releasing Hormone from the hypothalamus; however, LH secretion can also be stimulated by estradiol. LH works in concert with FSH to regulate female reproduction; FSH stimulates follicular growth and LH induces ovulation. LH also drives formation of the corpus luteum by promoting progesterone production. Additionally, LH has been suggested to stimulate the adrenal gland in postmenopausal women to induce secretion of sulfated DHEA, a precursor to androgens. In the testis, LH induces Leydig cell production of testosterone. Hypersecretion of LH has been shown to occur in women with polycystic ovary syndrome and is associated with an increased risk of infertility and miscarriage. Additionally, increased serum LH levels are associated with decreased cognition and have been implicated in the development and progression of Alzheimer’s disease. receptor into an A-frame... Read More | Purity＞97% by SDS-PAGE and HPLC analyses.FunctionPigment epithelium-derived factor (PEDF) is encoded by the SERPINF1 gene in humans and found in verebrates. It is a secreted phosphoglycoprotein that belongs to the clade F subfamily, serpin superfamily of proteinase inhibitors. The PEDF is a Purity＞97% by SDS-PAGE and HPLC analyses.FunctionPigment epithelium-derived factor (PEDF) is encoded by the SERPINF1 gene in humans and found in verebrates. It is a secreted phosphoglycoprotein that belongs to the clade F subfamily, serpin superfamily of proteinase inhibitors. The PEDF is a noninhibitory serpin with neurotrophic, anti-angiogenic, and anti-tumorigenic properties. It is synthesized as a 418 a.a. about 50kDa precursor that contains a 19 a.a. signal sequence and a 399 a.a. mature region that shows a pyroglutamate at Gln20. Like other serpins, it contains three β-sheets, 810 α-helices, and a C-terminal RCL (reactive center loop). Unlike other serpins with Ser protease inhibiting activity. PEDF has functions of inducing extensive neuronal differentiation in retinoblastoma cells, inhibiting of angiogenesis. As it does not undergo the S (stressed) to R (relaxed) conformational transition characteristic of active serpins, it exhibits no serine protease inhibitory activity. PEDF is researched as a therapeutic candidate for treatment of such conditions as choroidal neovascularization, heart disease, and cancer... Read More |