title: Autolysis control and structural changes of purified ficin from Iranian fig latex with synthetic inhibitors.
abstract: The fig's ficin is a cysteine endoproteolytic enzyme, which plays fundamental roles in many plant physiological processes, and has many applications in different industries such as pharmaceutical and food. In this work, we report the inhibition and activation of autolysis and structural changes associated with reaction of ficin with iodoacetamide and tetrathionate using high-performance liquid chromatography (HPLC), ultra filtration membrane, and dynamic light scattering (DLS) methods. The ficin structural changes were also determined using UV-absorption, circular dichroism (CD), fluorescence spectroscopy, and differential scanning calorimetry (DSC) techniques. These techniques demonstrated that iodoacetamide completely inhibited ficin autolysis, which was irreversible. However, tetrathionate partially and reversibility inhibited its autolysis. The ficin structural changes with two synthetic inhibitors were associated with secondary structural changes related to decreased alpha-helix and increased beta sheet and random coil conformations, contributing to its aggregation.
authors.affiliation: Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran; Estahban Fig Research Station, Fars Agricultural and Natural Resources Research and Training Center, AREEO, Shiraz, Iran.
authors.forename: H
authors.initials: H
authors.lastname: Zare
authors.affiliation: Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran; Center of Excellence in Biothermodynamics (CEBiotherm), University of Tehran, Tehran, Iran. Electronic address: moosavi@ut.ac.ir.
authors.forename: A A
authors.initials: AA
authors.lastname: Moosavi-Movahedi
authors.affiliation: Institute of Biochemistry and Biophysics (IBB), University of Tehran, Tehran, Iran; Department of Food Science and Engineering, University College of Agriculture & Natural Resources, University of Tehran, Karaj, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Salami
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA; Department of Pharmacology, University of Wisconsin School of Medicine and Public Health, Madison, WI, USA.
authors.forename: N
authors.initials: N
authors.lastname: Sheibani
authors.affiliation: Faculty of Biological Sciences, Department of Biochemistry, Tarbiat Modares University, Tehran, Iran.
authors.forename: K
authors.initials: K
authors.lastname: Khajeh
authors.affiliation: School of Biology, University of Tehran, Tehran, Iran.
authors.forename: M
authors.initials: M
authors.lastname: Habibi-Rezaei
mesh_terms: D002152:Calorimetry, Differential Scanning; D002851:Chromatography, High Pressure Liquid; D002942:Circular Dichroism; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D005361:Ficain / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D030681:Ficus / Q000737:chemistry*; D006868:Hydrolysis; D007840:Latex / Q000737:chemistry*; D066329:Protein Aggregates; D013057:Spectrum Analysis / Q000379:methods; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D007840:Latex; D066329:Protein Aggregates; D005361:Ficain
keywords: Autolysis; Ficin; Inhibition