Kinetics studies with fruit bromelain (Ananas comosus) in the presence of cysteine and divalent ions.
The kinetics of cysteine and divalent ion modulation viz. Ca(2+), Cu(2+), Hg(2+) of fruit bromelain (EC 3.4.22.33) have been investigated in the present study. Kinetic studies revealed that at pH 4.5, cysteine induced V-type activation of bromelain catalyzed gelatin hydrolysis. At pH 3.5, Ca(2+) inhibited the enzyme noncompetitively, whereas, both K-and V-type activations of bromelain were observed in the presence of 0.5 mM Ca(2+) at pH 4.5 and 7.5. Bromelain was inhibited competitively at 0.6 mM Cu(2+) ions at pH 3.5, which changed to an uncompetitive inhibition at pH 4.5 and 7.5. An un-competitive inhibition of bromelain catalyzed gelatin hydrolysis was observed in the presence of 0.6 mM Hg(2+) at pH 3.5 and 4.5. These findings suggest that divalent ions modulation of fruit bromelain is pH dependent.
Department of Biochemistry, School of Biotechnology and Biosciences, Lovely Professional University, 144401 Phagwara, Punjab India.
Tajwinder
T
Kaur
Department of Biochemistry, School of Biotechnology and Biosciences, Lovely Professional University, 144401 Phagwara, Punjab India.
Amandeep
A
Kaur
Department of Biochemistry, School of Biotechnology and Biosciences, Lovely Professional University, 144401 Phagwara, Punjab India.
Ravneet K
RK
Grewal
Ananas Comosus; Bromelain kinetics; Competitive inhibition; K-type activation; Uncompetitive inhibition; V-type activation