[Resonance scattering spectral assay of papain enzymatic activity with sodium dodecyl benzene sulfonate].
In pH 6.5 phosphate buffer solutions, dodecyl benzene sulfonate (SDBS) was combined with casein to form association particles, which exhibited five Rayleigh scattering peaks at 470, 360, 400, 420 and 520 nm, respectively. Under suitable conditions, papain has catalytic effect on the hydrolysis of casein, and SDBS can stop the catalytic reaction and be combined with the excess casein to form association particles. The scattering peak at 470 nm decreased with the activity of papain. The delta I470 value was linear with the papain activity in the range of 0.048-4.8 USP x mL(-1). Its regress equation is delta I(SDBS) = 1.972c + 2.31, with a related coefficient of 0.9999 and detection limit of 0.020 USP x mL(-1). This new assay has been applied to the assay of the papain activity in food additive with satisfactory results.
Huang
Guo-xia
GX
School of Environment and Resource, Guangxi Normal University, Guilin 541004, China.
Jiang
Zhi-liang
ZL
Liang
Ai-hui
AH
Deng
Ye-cheng
YC
D055162:Biocatalysis; D010206:Papain / Q000032:analysis* / Q000378:metabolism; D012967:Sodium Dodecyl Sulfate / Q000737:chemistry*; D013057:Spectrum Analysis / Q000379:methods*
D012967:Sodium Dodecyl Sulfate; D010206:Papain