title: The D14 and R138 ion pair is involved in dimeric arginine kinase activity, structural stability and folding.
abstract: Arginine kinase (AK) is a key enzyme in cellular energy metabolism of invertebrates. There are two conserved amino acid residues D14 and R138 in dimeric AK which form inter-subunit hydrogen bond. In Stichopus japonicus AK, mutations in these residues caused pronounced loss of activity, conformational changes and distinct substrate synergism alteration. Mutations (R138G, R138A and D14G) abolished D14 and R138 interaction disrupted the structure or conformation of S. japonicus AK. These R138G, R138A and D14G mutations changed their native assembles of dimeric AK and caused them in a partially unfolded state. The partially unfolded state of these mutant AKs made them prone to aggregate under environmental stress. The D14E/R138K and R138K mutant AKs showed similar characteristics to those of WT AK for forming the interaction which could replacement roles of D14 and R138 interaction. These results suggested that D14 and R138 interaction is involved in AK's activity, substrate synergism and structural stability.
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Hong-Li
authors.initials: HL
authors.lastname: Geng
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Mei-Ru
authors.initials: MR
authors.lastname: Bian
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Jiang
authors.initials: J
authors.lastname: Cao
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Chong
authors.initials: C
authors.lastname: Chen
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Zhi-Yuan
authors.initials: ZY
authors.lastname: Wang
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Zhen-Yu
authors.initials: ZY
authors.lastname: Li
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China.
authors.forename: Ling-Yu
authors.initials: LY
authors.lastname: Zeng
authors.affiliation: College of Life Sciences, State Key Laboratory of Crop Biology, Shandong Agricultural University, Tai'an, Shandong 271018, People's Republic of China. Electronic address: xyunwangsdau@163.com.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Laboratory of Transplantation and Immunology, Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of China. Electronic address: qywu82@163.com.
authors.forename: Qing-Yun
authors.initials: QY
authors.lastname: Wu
authors.affiliation: Department of Hematology, The Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, China. Electronic address: lihmd@163.com.
authors.forename: Kai-Lin
authors.initials: KL
authors.lastname: Xu
mesh_terms: D000596:Amino Acids / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001122:Arginine Kinase / Q000235:genetics / Q000378:metabolism*; D006860:Hydrogen Bonding; D007477:Ions / Q000378:metabolism*; D007700:Kinetics; D009154:Mutation / Q000235:genetics; D017510:Protein Folding; D017433:Protein Structure, Secondary / Q000235:genetics; D017434:Protein Structure, Tertiary / Q000235:genetics; D047528:Stichopus / Q000201:enzymology* / Q000378:metabolism; D013379:Substrate Specificity / Q000235:genetics
chemical_list: D000596:Amino Acids; D007477:Ions; D001122:Arginine Kinase
keywords: Arginine kinase; Folding; Structural stability