Abstract
Nowadays, plant cysteine proteinase inhibitors "namely phytocystatins" have attracted researchers towards the identification of their molecular structures and novel physiological functions. Their important roles in plant developmental processes and different stress responses have been well known. In spite of advances in the understanding of phytocystatins, we lack enough data concerning their heterologous expression especially in the forms of fusion products that are most important whether for biochemical, pharmacological or clinical studies. The present work describes an easy method of expression, purification and functional characterization in Escherichia coli of maize cystatin as a part of maltose-binding fusion protein. Assessments revealed that upon expression of fused product the total antioxidation status of the induced recombinant cells is increased. This result leads to question 'Is there any parallel functional correlation between anti-proteolytic and anti-oxidative systems?' However, the present research will open a gate for the new studies regarding the putative communicative roles of these systems that may be existing in the biological world.