Complete knockout of the lactate dehydrogenase A gene is lethal in pyruvate dehydrogenase kinase 1, 2, 3 down-regulated CHO cells.

Accumulation of high level of lactate can negatively impact cell growth during fed-batch culture process. In this study, we attempted to knockout the lactate dehydrogenase A (LDHA) gene in CHO cells in order to attenuate the lactate level. To prevent the potential deleterious effect of pyruvate accumulation, consequent to LDHA knockout, on cell culture, we chose a pyruvate dehydrogenase kinase 1, 2, and 3 (PDHK1, 2, and 3) knockdown cell line in which to knock out LDHA alleles.

Chinese hamster ovary K1 host cell enables stable cell line development for antibody molecules which are difficult to express in DUXB11-derived dihydrofolate reductase deficient host cell.

Therapeutic monoclonal antibodies (mAb) are often produced in Chinese hamster ovary (CHO) cells. Three commonly used CHO host cells for generating stable cell lines to produce therapeutic proteins are dihydrofolate reductase (DHFR) positive CHOK1, DHFR-deficient DG44, and DUXB11-based DHFR deficient CHO. Current Genentech commercial full-length antibody products have all been produced in the DUXB11-derived DHFR-deficient CHO host.

Cloning, expression and functional characterization of cytochrome P450 3A37 from turkey liver with high aflatoxin B1 epoxidation activity.

Cytochrome P450s (P450) play an important role in the formation of carcinogenic and mutagenic electrophilic intermediates from a wide range of xenobiotics, including naturally occurring dietary compounds. The pathogenesis of hepatotoxic and hepatocarcinogenic action of the mycotoxin aflatoxin B(1) (AFB(1)) involves initial bioactivation by P450s to a reactive and electrophilic intermediate exo-aflatoxin B(1)-8,9-epoxide (exo-AFBO). Poultry, especially turkeys are extremely sensitive to AFB(1), a condition due, in part, to efficient epoxidation by P450 1A and 3A enzymes.

Molecular cloning and expression of a novel cytochrome p450 from turkey liver with aflatoxin b1 oxidizing activity.

Cytochromes P450 are members of a superfamily of oxidative hemoprotein enzymes that metabolize a variety of endogenous and exogenous compounds. Previous studies in our laboratory have shown that efficient P450-mediated activation underlies the extreme sensitivity of poultry, specifically turkeys, to the toxic effects of the mycotoxin aflatoxin B1 (AFB1). Using 3'- and 5'-rapid amplification of cDNA ends (RACE), we amplified from turkey liver RNA a full-length 1.