Measurement of Glucose 6 phosphate Dehydrogenase Activity in Bacterial Cell free Extracts

Karakaya H., Özkul K.

BIO-PROTOCOL, cilt.6, sa.19, 2016 (Hakemli Dergi)

  • Yayın Türü: Makale / Teknik Not
  • Cilt numarası: 6 Sayı: 19
  • Basım Tarihi: 2016
  • Doi Numarası: 10.21769/bioprotoc.1949
  • Dergi Adı: BIO-PROTOCOL
  • Ondokuz Mayıs Üniversitesi Adresli: Evet

Özet

Glucose-6-phosphate dehydrogenase (G6PDH) (EC 1.1.1.49) is the first enzyme of the
oxidative pentose phosphate cycle and catalyses the conversion of glucose-6-phosphate (G6P) to 6-
phosphoglucono-δ-lactone and transfers one electron to NADP+ producing one NADPH. Conversion of
G6P to 6-phosphoglucono-δ-lactone is proportional to the production of NADPH. The increase in
NADPH concentration results in an increase in absorbance at 340 nm. To assay G6PDH activity,
therefore, production of NADPH is determined by measuring increase in absorbance at 340 nm
spectrophotometrically. This increase rate is then converted to unit of activity and specific activity of
G6PDH. In this procedure, a generalized method is given for bacterial G6PDH assays emphasizing on
a cyanobacterium Synechocystis sp. PCC6803 (Schaeffer and Stanier, 1978; Karakaya et al., 2008,
2012) and a heterotrophic bacterium E.coli (Hylemon and Phibbs, 1972; Barnel et al., 1990).