205-210<span style="font-size:14.0pt;line-height:
115%;font-family:" times="" new="" roman";mso-fareast-font-family:"times="" roman";="" mso-ansi-language:en-in;mso-fareast-language:en-in;mso-bidi-language:hi"="" lang="EN-IN">Kinetic
properties of rat liver acid phosphatase were evaluated using the conventional
synthetic substrates sodium beta glycerophosphate (βGP) and p-nitrophenyl
phosphate (PNPP) and physiologically occurring phosphate esters of
carbohydrates,vitamins and nucleotides. The extent of hydrolysis varied
depending on the substrates; phosphate esters of vitamins and carbohydrates
were in general poor substrates. Kinetic analysis revealed the presence of two
components of the enzyme for all the substrates. Component I had low Km
and low Vmax. Opposite was true for component II. The Km
values were generally high for βGP, PNPP and adenosine diphosphate (ADP).
Amongst the nucleotides substrates AMP showed high affinity i.e. low Km.
The increase in enzyme activity in general at high substrate concentrati on
seems to be due to substrate binding and positive cooperativity. AMP which
showed highest affinity was inhibitory at high concentration beyond 1mM.
The results suggest that in situ the nucleotides may be the preferred
substrates for acid phosphatase.</span