DHFR, also known as Dihydrofolate reductase, is an enzyme that reduces dihydrofolic acid to tetrahydrofolic acid, using NADPH as electron donor, which can be converted to the kinds of tetrahydrofolate cofactors used in 1-carbon transfer chemistry. Dihydrofolate reductase deficiency has been linked to megaloblastic anemia. Source: Recombinant protein corresponding to aa1-187 from human DHFR, fused to His-Tag at N-terminal, expressed in E. coli. Molecular Weight: ~23.6kD (207aa), confirmed by MALDI-TOF. Amino Acid Sequence: MGSSHHHHHH SSGLVPRGSH MVGSLNCIVA VSQNMGIGKN GDLPWPPLRN EFRYFQRMTT TSSVEGKQNL VIMGKKTWFS IPEKNRPLKG RINLVLSREL KEPPQGAHFL SRSLDDALKL TEQPELANKV DMVWIVGGSS VYKEAMNHPG HLKLFVTRIM QDFESDTFFP EIDLEKYKLL PEYPGVLSDV QEEKGIKYKF EVYEKND Specific Activity: >3500pmol/min/ug, and is defined as the amount of enzyme that converts 1pmole of dihydrofolic acid to tetrahydrofolic acid/minute at pH 6.5 at 25C. Storage and Stability: May be stored at 4C for short-term only. Aliquot to avoid repeated freezing and thawing.. Store at -20C. Aliquots are stable for 6 months after receipt at -20C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.