Characterization of acid-induced partially folded conformation resembling a molten globule state of polygalacturonase from a filamentous fungus Tetracoccosporium sp.
Acid-induced unfolding of a Tetracoccosporium sp. polygalacturonase enzyme (PG) was studied by a comprehensive series of biophysical and biochemical techniques. At pH 1.0, PG acquires partially folded state, which reveals characteristics of molten globule (MG) state, i.e., reduction of defined tertiary structure with minimal changes in the secondary structure. In this study PG unfolds exposing its hydrophobic surface to a greater extent than the native form at acidic pH with more tryptophan residues exposed to the solvent. Collectively, our data imply the presence of MG state of PG at low pH, suggesting the phenomenon of hydrophobic collapse model for folding and integration into cell membrane.
Aminzadeh
Saeed
S
National Institute of Genetic Engineering and Biotechnology, Pajoohesh Blvd., Tehran-Karaj Highway, 17th km, Tehran, Iran.
Naderi-Manesh
Hossein
H
Khajeh
Khosro
K
Ranjbar
Bijan
B
Farrokhi
Naser
N
D000143:Acids / Q000737:chemistry*; D004789:Enzyme Activation; D005453:Fluorescence; D005658:Fungi / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D011096:Polygalacturonase / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D011487:Protein Conformation; D011489:Protein Denaturation; D017510:Protein Folding; D013045:Species Specificity
D000143:Acids; D011096:Polygalacturonase