Lysosomes are subcellular organelles which perform many important cellular functions. For example, lysosomes digest foreign material and engulfed viruses and bacteria presenting in phagosomes during the process of phagocytosis. In addition, lysosomes destroy targeted organelles, such as mitochondria, and injured cells via autolysis. Autolysis plays a central role in many apoptotic cascades.... More Info
Deubiquitinating Enzymes (DUBs)
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Protein ubiquitination is a reversible process. The deconjugation reactions are performed by specific cysteine proteases which generate monomeric ubiquitin from a variety of C-terminal adducts. Deubiquitinating enzymes (DUBs) are the largest family of enzymes in the ubiquitin system with diverse functions, making them key regulators of ubiquitin-mediated pathways... More Info
E2 Ubiquitin/Ubl Conjugating Enzymes
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E2 proteins have various individual and redundant roles within the cell and have important roles in target degradation (proteasomal pathways) and target modification for regulatory purposes (non-proteasomal pathways). The biochemical process of Ub/UBL conjugation is initiated by the ATP-dependent E1 enzyme, followed by transfer to the active site cysteine of E2... More Info
DNA Modifying Enzymes
Eukaryotic and prokaryotic cells possess multiple mechanisms to repair DNA and control damage to their genomes. These include base excision repair (BER) and nucleotide excision repair (NER) that excise and replace damaged nucleotide bases and helix-distorting lesions, respectively. Many of the enzymes involved in NER are also active in transcription-coupled repair (TCR) processes. In addition,... More Info
DNA Damage Repair Enzymes
DNA Damage Repair Enzymes are necessary for the repair of errors introduced during DNA replication or recombination or as a result of treatment with exogenous genotoxic agents. These enzymes can be used in vitro to detect specific forms of DNA damage or for repair assays. The DNA damage repair substrates are oligonucleotides that contain specific mutations which are recognized and cleaved by some... More Info
Cell Culture Studies
The physical and pathological role a recombinant protein plays is often measured in cell culture. As mentioned previously, it is essential that the protein is functionally active and free of contaminants for the response to be informative. Numerous bioassay protocols are available. Contact the R&D Systems’ Technical Service Department if your protocol of interest is not... More Info
Protein Biological Activity
At R&D Systems, recombinant proteins are sold in units of mass per vial (µg or mg) with a specific activity range rather than as units of activity per vial.
How is Activity Measured?
The biological activity of a recombinant protein is routinely measured using a bioassay, e.g. chemotaxis or cell proliferation assay, enzyme assay, or a functional ELISA. Due to a protein’s ability to exert... More Info
Macrophage Stimulating Protein (MSP)
First printed in R&D Systems' 1998 Catalog.
The macrophage plays a variety of roles in the immune defense system, including a central role in innate or natural immunity. First described as a phagocyte by Metchnikoff in the 1800's1, 2, this cell is now known to exhibit a wide variety of functions, including phagocytosis, tumor cytotoxicity, cytokine secretion and (possibly) antigen... More Info
Calcium-binding Proteins and Related Molecules
Calcium ions act as second messengers to control a broad range of physiological effects. Deregulation of intracellular calcium levels can result in irreversible injury and has been implicated in several disease conditions. Thus, calcium homeostasis, the control of intracellular Ca2+ concentration, is very tightly regulated. Calcium functions as an effector signaling molecule by modulating the... More Info
Welcome to our Summer Protein Update
Recombinant Human DLL3 Now AvailableDelta-like protein 3 (DLL3) is a transmembrane protein that belongs to the Delta/Serrate/Lag-2 (DSL) family of Notch ligands. It has received much recent attention due to its potential as a target for small cell lung cancer.
New Active Enzymes: Arginase-2 and Lipoprotein LipaseMetabolic enzymes and their associated pathways... More Info