Pyruvate dehydrogenase [NADP(+)] is one of three enzymes participating in respiratory metabolism. The enzyme is also active with 2-oxobutyrate and oxaloacetate. The enzyme is oxygen sensitive. CoA + NADP(+) + pyruvate = acetyl-CoA + CO2 + NADPH Binds 1 FAD per subunit. Binds 1 FMN per subunit. Optimum pH is 7.5. Optimum temperature is 40 degrees Celsius. Homodimer. Expressed in both aerobic and anaerobic conditions. Arose from gene fusion of pyruvate:ferredoxin oxidoreductase and cytochrome-P450 reductase. Gene fusion has only been found in Euglena and Cryptosporidium. Euglena cells absolutely require thiamine for growth due to the lack of a pyrimidine formation biosynthetic pathway. Thiamine is actively taken up into the cells and is used as a cofactor after being converted to TPP (thiamine pyrophosphate). In the N-terminal section; belongs to the pyruvate:ferredoxin/flavodoxin oxidoreductase family.