Kinetic properties of $alpha$-D-galactosidase from watermelon (Citrullus vulgaris)

Abstract

The kinetic properties of $\alpha$-D-galactosidase purified from watermelon (Citrullus vulgaris) were studied. Kinetic parameters were determined by using raffinose and p-nitrophenyl-$\alpha$-D-galactopyranoside as natural and synthetic substrates, respectively. The Km and Vmax values were 9.1x$10^{-1}$ mM and 7.14x$10^{-2}$ p.rnolmin-1 for p-nitrophenyl-$\alpha$-D-galactopyranoside and 7.1x$10^{-2}$ mM and 2.9x$10^{-3}$ $\mu molmin^{-1}$ for raffinose. The inhibition kinetics of D-galactose on the enzyme was also investigated. The type of inhibition caused by D-galactose was found as competitive.Karpuzdan (Citrullus vulgaris) saflaştırılan $\alpha$-D-galaktosidazın kinetik özellikleri incelendi. Kinetik parametreler, doğal ve sentetik substrat olarak rafinoz ve p-nitrofenil-$\alpha$-D-galaktopiranozid kullanılarak belirlendi. $K_m$ ve $V_ {max}$ değerleri sırasıyla p-nitrofenil-$\alpha$-D-galaktopiranozid için 9,1x$10^{-1}$ mM ve 7,14x$10^{-2}$ $\mu molmin^{-1}$ ve rafinoz için 7,1x$10^{-2}$ ve 2,9x$10^{-3}$ $\mu molmin^{-1}$ olarak hesaplandı. Ayrıca D-galaktozun enzim üzerine olan inhibisyon kinetikleri araştırıldı. D-galaktozun neden olduğu inhibisyon tipi kompetitif olarak bulundu