Human Erythrocyte Acetylcholinesterase Inhibition by Porphyrin Compounds

Study of erythrocyte membrane Acetylcholinesterase(AChE) inhibition is a biomarker of toxicity of chemical compounds. Three Porphyrin derivatives, Tetraphenylporphinesulfonate (TPPS), 5,10,15,20-Tetrakis (4 sulfonatophenyl) porphyrinato Iron(III) Chloride (FeTPPS) and 5,10,15,20-Tetrakis (4-sulfonatophenyl) porphyrinato Iron(III) nitrosyl Chloride (FeNOTPPS), were chemically synthesized and tested against human erythrocyte AChE by enzymatic assays. The results show that FeNOTPPS forms the most stable complex with AChE. The activity of AChE dropped by almost -20%upon addition of 10-10 M FeNOTPPS. The differential effects of Porphyrin compounds can be accounted for by fluidity changes in the erythrocyte cell membrane.