Proteins & Enzymes

136 Results Found

Purified Human Lactoferrin

Product is the lyophilized powder of human lactoferrin and buffer salts. Human lactoferrin is purified from pooled human colostrum using multi-step procedures which may include salt fractionation, gel filtration, ion-exchange chromatography and immunoabsorption.

Lactoferrin

Lactoferrin is an iron binding protein. It is structurally similar to transferrin, the plasma iron transport protein; but lactoferrin has a much higher affinity for iron (250 fold). It is very abundant in colostrum and small amounts can also be found in tears, saliva, mucous secretions and in the secondary granules of neutrophils. It is made by mucosal epithelium and neutrophils and is released by these cells in response to inflammatory stimuli. Bacterial growth is inhibited by its ability to sequester iron and also permeabilize bacterial cell walls by binding to lipopolysaccharides through its N-terminus. Lactoferrin can inhibit viral infection by binding tightly to the viral envelope protein. This prevents cell-virus fusion by blocking the binding domain. Lactoferrin appears to activate host defense systems in part by stimulating the release of interleukin-8, a neutrophil activator. It may also be involved in antibody and interleukin synthesis, lymphocyte proliferation and complement activation.

Lactoferrin

Lactoferrin is an iron binding protein. It is structurally similar to transferrin, the plasma iron transport protein; but lactoferrin has a much higher affinity for iron (250 fold). It is very abundant in colostrum and small amounts can also be found in tears, saliva, mucous secretions and in the secondary granules of neutrophils. It is made by mucosal epithelium and neutrophils and is released by these cells in response to inflammatory stimuli. Bacterial growth is inhibited by its ability to sequester iron and also permeabilize bacterial cell walls by binding to lipopolysaccharides through its N-terminus. Lactoferrin can inhibit viral infection by binding tightly to the viral envelope protein. This prevents cell-virus fusion by blocking the binding domain. Lactoferrin appears to activate host defense systems in part by stimulating the release of interleukin-8, a neutrophil activator. It may also be involved in antibody and interleukin synthesis, lymphocyte proliferation and complement activation.

Lactoferrin

Lactoferrin is an iron binding protein. It is structurally similar to transferrin, the plasma iron transport protein; but lactoferrin has a much higher affinity for iron (250 fold). It is very abundant in colostrum and small amounts can also be found in tears, saliva, mucous secretions and in the secondary granules of neutrophils. It is made by mucosal epithelium and neutrophils and is released by these cells in response to inflammatory stimuli. Bacterial growth is inhibited by its ability to sequester iron and also permeabilize bacterial cell walls by binding to lipopolysaccharides through its N-terminus. Lactoferrin can inhibit viral infection by binding tightly to the viral envelope protein. This prevents cell-virus fusion by blocking the binding domain. Lactoferrin appears to activate host defense systems in part by stimulating the release of interleukin-8, a neutrophil activator. It may also be involved in antibody and interleukin synthesis, lymphocyte proliferation and complement activation.

Hyaluronidase (From Streptomyces Hyalurolyticus)

Synonyms: Hyaluronate lyase; Hyaluronidase; Mucinase. The hyaluronidase is purified from Streptomyces hyalurolyticus. This enzyme belongs to the endo-beta-hexosaminidase and endo-eliminase type enzyme that produces oligo-saccharide (unsaturated tetraose and pentose) by hydrolyzing the beta-1,4-linkage of hyaluronic acid. Hyaluronidase is stable in both high temperature and acid or alkaline range. It has high substrate specificity and hydrolyzes hyaluronic acid only in mucopolysaccharide. From Streptomyces hyalurolyticus
Lyophilized, salt-free
Activity: ∼2000 units/mg
Protease and lysozyme free
Each vial contains 100 U
Enzyme activity is determined by a change in optical density in a hyaluronic acid solution. It is compared to a hyaluronidase International Standard expressed as I.U.
See Enzymes and Substrates in the Immunobiologicals section for further details.

Human Transferrin Iron Saturated

Transferrin is a glycoprotein with homologous N-terminal and C-terminal iron-binding domains.

Human Transferrin Iron Poor (APO)

Transferrin is a glycoprotein with homologous N-terminal and C-terminal iron-binding domains.

Prostate Specific Antigen

The human Prostate Specific Antigen (PSA) is supplied in a 0.02M phosphate buffer with 0.15M sodium chloride, pH 7.3 and 0.05% sodium azide as preservative. It is sterile filtered through a 0.2 mM membrane.

Purified Human Transferrin

Product is the lyophilized powder of human transferrin and buffer salts. ransferrin is a glycoprotein with homologous N-terminal and C-terminal iron-binding domains. The N-terminal and C-terminal domains of this protein are globular moieties of about 330 amino acids. Each of these domains is divided into two sub-domains, with the iron- and anion-binding sites found within the intersubdomain cleft. The binding cleft opens with iron release and closes with iron binding. Transferrin binds iron with an association constant of approximately 1022 M-1. Ferric iron couples to transferrin only in the presence of an anion (usually carbonate) that serves as a bridging ligand between metal and protein, excluding water from the two coordination sites. Without the anion cofactor, iron binding to transferrin is negligible. In the presence of anions, ferric transferrin is resistant to all but the most potent chelators. The remaining four coordination sites are provided by the transferrin protein - a histidine nitrogen, an aspartic acid carboxylate oxygen, and two tyrosine phenolate oxygens. Available evidence suggests that anion-binding takes place prior to iron-binding. Iron release from transferrin involves protonation of the carbonate anion, loosening the metal-protein bond.

Purified Human Hemoglobin

Product is the lyophilized powder of human hemoglobin and buffer salts.

Purified Human Fibronectin

Product is human fibronectin and buffer salts.

Human Albumin (10% Solution)

10% Solution
Prepared from Fraction V human albumin, this solution is supplied at a pH of 7.1 ±0.3 and contains 0.05% sodium azide as a preservative.
See the Immunobiologicals Section for additional details.

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Human Albumin, Fraction V Fatty Acid Free

Albumin may be used to eliminate background interference in ELISA's or other enzyme assay systems. It is also used in absorption, distribution, metabolism, and excretion (ADME) pharmacological research; cell culture; drug delivery research; and cryopreservation of cells. This protein is prepared by a modification of the Chen low pH charcoal method. Contains < 0.1 mg/g fatty acids. The venous blood from which this product is manufactured has been tested for the presence of Hepatitis B Surface Antigen (HBsAg) and found to be non-reactive by a currently approved FDA test. The blood has also been tested for the presence of Anti-HCV, Anti-HIV-1 and Anti-HIV-2, antibodies and found to be negative. The source donors have been tested in accordance with 21 CFR 640. This blood is non-reactive for syphilis.

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Human Albumin Fraction V

This human protein is prepared by a modification of the Cohn procedure. Albumin may be used to eliminate background interference in ELISA's or other enzyme assay systems. It is also used in absorption, distribution, metabolism, and excretion (ADME) pharmacological research; cell culture; drug delivery research; and cryopreservation of cells. Human and bovine albumins contain 16% nitrogen and are often used as standards in protein calibration studies. Due to their free hydrophobic region fatty acid free albumins are used to solubilize lipids in tissue culture, and are also used as blocking agents in Western blots or ELISA applications. Globulin free albumins are suitable for use in applications where no other proteins should be present (e.g., electrophoresis). Serum albumin functions as a carrier protein for steroids, fatty acids, and thyroid hormones, and is vital in regulating the colloidal osmotic pressures of blood. Albumin is also seen to bind to exogenous substances, particularly drugs (e.g., ibuprofen, warfarin), and strongly influence their pharmacokinetics. Oxidative stress leading to changes in the redox state of albumin has widely varied effects on its physiological function.

Fluorescein-Conjugated Human Albumin

Product is the lyophilized powder of fluorescein-5-isothiocyanate (FITC "Isomer I")-conjugated human albumin and buffer salts.

Horseradish Peroxidase-Conjugated Avidin

Product is a 2 ml solution containing 5 mg horseradish peroxidase(HRP)-conjugated egg white avidin.

Streptavidin-Fitc

This is a purified product supplied in 0.05% sodium azide. The typical working dilution is 1:50-1:150.

Alpha-Fetoprotein (Afp) Antigen

From Human Cord Serum
Iodination Grade
Purity: >97%

This antigen is ideal for labeling or immunization purposes. The antigen is in 0.1M Sodium Phosphate buffer, 0.2M NaCl, pH 7.4, with 0.05% sodium azide as preservative.

Proline Specific Endopeptidase (From Flavobacterium Meningosepticum)

Proline Specific Endopeptidase specifically cleaves peptide bonds on the carboxy side of proline residues. Much slower hydrolysis is observed on the carboxy side of alanine residues. This enzyme is very close, in its properties, to a post-proline cleaving enzyme. The substrates have been found to have the general structure Y-Pro-X, where Y is a peptide or N-protected amino acid and X may be an amino acid, peptide, amide or ester.