title: Amino acids flanking the central core of Cu,Zn superoxide dismutase are important in retaining enzyme activity after autoclaving.
abstract: Enzymes are known to be denatured upon boiling, although Cu,Zn superoxide dismutase of Potentilla atrosanguinea (Pot-SOD) retains significant catalytic activity even after autoclaving (heating at 121 °C at a pressure of 1.1 kg per square cm for 20 min). The polypeptide backbone of Pot-SOD consists of 152 amino acids with a central core spanning His45 to Cys145 that is involved in coordination of Cu(2+) and Zn(2+) ions. While the central core is essential for imparting catalytic activity and structural stability to the enzyme, the role of sequences flanking the central core was not understood. Experiments with deletion mutants showed that the amino acid sequences flanking the central core were important in retaining activity of Pot-SOD after autoclaving. Molecular dynamics simulations demonstrated the unfavorable structure of mutants due to increased size of binding pocket and enhanced negative charge on the electrostatic surface, resulting in unavailability of the substrate superoxide radical ([Formula: see text]) to the catalytic pocket. Deletion caused destabilization of structural elements and reduced solvent accessibility that further produced unfavorable structural geometry of the protein.
authors.affiliation: a Biotechnology Division , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.
authors.forename: Arun
authors.initials: A
authors.lastname: Kumar
authors.affiliation: a Biotechnology Division , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|b Functional Genomics and Complex Systems Lab , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|e Academy of Scientific & Innovative Research (AcSIR) , New Delhi , India.
authors.forename: Vinay
authors.initials: V
authors.lastname: Randhawa
authors.affiliation: a Biotechnology Division , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|b Functional Genomics and Complex Systems Lab , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|e Academy of Scientific & Innovative Research (AcSIR) , New Delhi , India.
authors.forename: Vishal
authors.initials: V
authors.lastname: Acharya
authors.affiliation: c Department of Biotechnology , Panjab University , Chandigarh 160 014 , India.
authors.forename: Kashmir
authors.initials: K
authors.lastname: Singh
authors.affiliation: a Biotechnology Division , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|d Biodiversity Division , CSIR-Institute of Himalayan Bioresource Technology (Council of Scientific and Industrial Research) , Palampur 176 061 , Himachal Pradesh , India.|e Academy of Scientific & Innovative Research (AcSIR) , New Delhi , India.
authors.forename: Sanjay
authors.initials: S
authors.lastname: Kumar
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D020134:Catalytic Domain; D003300:Copper / Q000737:chemistry*; D004789:Enzyme Activation; D008958:Models, Molecular; D008968:Molecular Conformation; D056004:Molecular Dynamics Simulation; D011489:Protein Denaturation; D055550:Protein Stability; D017384:Sequence Deletion; D013329:Structure-Activity Relationship; D013482:Superoxide Dismutase / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D015032:Zinc / Q000737:chemistry*
chemical_list: D000596:Amino Acids; D003300:Copper; D013482:Superoxide Dismutase; D015032:Zinc
keywords: autoclave-stability; catalytic pocket; molecular dynamics; superoxide dismutase; superoxide free radical