Study and Application on Polarographic Catalytic Wave of Human Serum Albumin in the Presence of Kio₃

ABSTRACT

A polarographic catalytic wave of human serum albumin (HSA) in the presence of KIO³ was reported. In 0.1 M NaAc∼HAc buffer (pH4.7) solution, a reduction wave of HSA with peak potential −0.60 V (vs., Ag/AgCl) resulted from the reduction of five disulfide linkages to sulfhydryl group. In the presence of KIO³, HSA yielded a polarographic catalytic wave at the original potential due to reduction and regeneration of these disulfide linkages. The catalytic wave can be used to determine trace of HSA. In the 0.1 M HAc∼NaAc (pH4.7±0.2) ∼1×10⁻³ M KIO³ solution, the peak current was linearly proportional to HSA concentration in the range of 1.5×10⁻⁷∼7.5×10⁻⁷ M. The catalytic wave improved two orders of magnitude in sensitivity compared with corresponding reduction wave.

Keywords::

• human serum albumin (HSA)
• protein
• polarographic catalytic wave
• KIO³
• polarography