Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.2.1.13 (glyceraldehyde-3-phosphate dehydrogenase)
 6,511 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The demand for convenient and sensitive means of measuring cytotoxicity and complement-mediated killing is likely to be increased by the recent identification of Complement Factor H, an important regulatory protein of both the classical and alternate pathways of complement, as a tumor-associated antigen. Here we describe a simple luminometric assay capable of detecting the death of approximately 0.03 nucleated human-cell equivalent or approximately 1 rabbit-erythrocyte equivalent. The assay measures the release of glyceraldehyde-3-phosphate dehydrogenase (G3PDH) from dead or damaged cells by coupling its enzymatic activity to production of ATP, which in turn is measured by well-known methods involving firefly luciferase. This is accomplished by means of a reaction series in which the activity of G3PDH is coupled with that of phosphoglycerate kinase, the next enzyme in the glycolytic pathway. As described, the assay uses inexpensive, commercially available reagents. This coupled assay was used to demonstrate that an anti-factor-H antibody is capable of enhancing complement-mediated killing of the Raji cancer cell line by > 1000%.
 ...
PMID:A very sensitive coupled luminescent assay for cytotoxicity and complement-mediated lysis. 932 85

Mycoplasmas persist in the host for a long time, suggesting that they possess mechanisms for immune evasion. Factor H is a negative regulator of the complement system, which binds to host cells to avoid unexpected complement activation. In this study, we revealed that many mycoplasmas, such as Mycoplasma hyopneumoniae, Mycoplasma hyorhinis, Mycoplasma hyosynoviae, Mycoplasma gallisepticum, Mycoplasma pneumoniae, Mycoplasma genitalium, Mycoplasma flocculare, and Mycoplasma bovis could hijack factor H such that they present themselves as a host tissue and thus escape from complement attack. Furthermore, the mechanism of recruiting factor H was identified in M. hyopneumoniae. M. hyopneumoniae binds factor H via factor H binding proteins, such as elongation factor thermo unstable (EF-Tu), P146, pyruvate dehydrogenase (acetyl-transferring) E1 component subunit alpha (PdhA), P46, Pyruvate dehydrogenase E1 component subunit beta (PdhB), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), and three different hypothetical proteins. The binding of factor H by EF-Tu further contributes to decreased C3 deposition on the M. hyopneumoniae surface and ultimately blocks further complement activation. In fact, binding of factor H occurs in a multifactorial manner; factor H is not only exploited by M. hyopneumoniae via its regulator activity to help mycoplasmas escape from complement killing, but also increases M. hyopneumoniae adhesion to swine tracheal epithelial cells, partially through EF-Tu. Meanwhile, the high sequence identity among EF-Tu proteins in the above-mentioned mycoplasmas implied the universality of the mechanism. This is the first report that mycoplasmas can escape complement killing by binding to factor H.
 ...
PMID:Mycoplasma hyopneumoniae evades complement activation by binding to factor H via elongation factor thermo unstable (EF-Tu). 3281 70