The effect of amino acid enantiomers on activity of selected enzymes in soil

Abstract

This work was aimed to test the effect of selected amino acid enantiomers on activity of casein-protease and acid phosphomonoesterase in soil. Casein-protease was selected due to its key role in nitrogen mineralization and acid phosphomonoesterase due to its importance in soil organic P mineralization. The results showed that 5 mg of L- and D-glutamic acid added to fresh soil from Ah horizon of a moderately mown mountain meadow significantly (P < 0.05) decreased casein-protease activity, whereas alanine enantiomers slightly increased activity of this enzyme. Testing the effect of cystine on activity of acid phosphomonoesterase in soil showed slight increase of this activity after application of 3.2 mg L- or D-cystine to fresh soil (equivalent to 8 mg to dry soil).

Differential effects of D-amino acids on the fusion forms of a cysteine proteinase/cystatin pair

“…This is in agree ment with the reports of Dundek group with respect to the effect of D Ala on the activity of soil casein pro teinases [18]. Their experiment potentially suggests that D Ala directly interacts with proteinase and increases its activity.…”

“…Amino acids D Cys and D Ser have been found to decrease asparic type HIV proteinase activity in the treated cells or tis sues [16]. In addition, the soil casein proteinase activi ties have also been found to be differentially affected by amino acids D Glu acid and D Ala [18].…”

“…Despite this, the experiment result indicates that all test D amino acids have the same effects on the fusion product of CP/CPI in which CPI molecule located upstream of CP. In a recent research work, the differential effects of two D amino acids including D Ala and D Glu have been reported on the activity of soil casein proteinases [18]. It has been shown the D Ala increased the activity of soil protein ase, but D Glu decreased it.…”

“…The effects of D and L enantiomers of Ala and Glu on the activity of soil casein proteinases have also been tested not long ago [18]. It has been revealed that D Glu highly inhibits the activities of soil proteinases, while D Ala slightly increases their activities.…”