Determination of the activity and kinetics parameters of proteases in the crude plant extracts of Mentha piperita L. and Thymus capitatus L.

Abstract

The present study provides plant-derived extracts to characterize the activity and kinetics of protease enzymes of Mentha piperita L and Thymus capitatus L. The results illustrated that these crude extracts have a proteolytic activity within optimum pH (3-9) and optimum temperature (35-50°C). The study of the ionizable groups in or around the active site of these proteases by Dixon-Webb's plot reveals the occurrences or the presence of aspartic acid with pKa 1 at pH 2.9 and pKa 2 at pH 3.2, and cysteine amino acids in or around the active site with pKa 1 at pH 6.7 and pKa 2 at pH 7.2; interestingly, these proteases maybe belonged to the acid proteases and neutral proteases. Enzymatic kinetics studies (k m , V max, V max /k m) indicated that egg albumin is a good substrate for proteases of M. piperita L. and T. capitatus L.

Purification and Characterization of Alkaline Protease Isolated from Cotton (Gossypium hirsutum) Seeds

“…The activity of protease increases with the increase of substrate concentration also reported from Carica papaya latex using azocasien as a substrate (Diana R Baidamshina et al, 2021). It is also reported by other workers and correspondence with reported values from Mentha piperita L and Thymus capitatus L using egg albumin as a substrate and from Moringa oleifera leaves using β-casein as a substrate (Atrooz & Alomari, 2020;Banik, Biswas, & Karmakar, 2018).…”

“…A Lineweaver-Burk plot for casein was linear suggesting that the rate of proteolysis was The Km value of the present report is also lower than reported by other workers obtained from protease enzymes of some other plants like field bean seeds enzyme 0.0105M (Paul & Gowda, 2000), 0.107M from Moringa oleifera leaves (Banik et al, 2018), 0.02M from the seeds of Cucumismelovaragrestic (Devi & HemaLatha, 2014) and 0.19M from Yemeni bean seeds (Maqtari, Naji, & Ali). However, the value of Vmax is higher in the present study as reported in Table 3 than those of calculated from Sorghum malt protease which was 8.2 μmol/minute (Ogbonna & Okolo, 2005), Mentha piperita L protease, 2.94 μmol/minute and Thymus capitatus L protease 1.3 μmol/minute (Atrooz & Alomari, 2020).…”