title: T273 plays an important role in the activity and structural stability of arginine kinase.
abstract: Arginine kinase (AK) is a key enzyme for cellular energy metabolism, catalyzing the reversible phosphoryl transfer from phosphoarginine to ADP in invertebrates. The amino acid residue C271 is involved in keeping AK's activity and constraining the orientation of the substrate arginine. However, the roles of the C271 interaction amino acid residues in AK's substrate synergism, activity and structural stability are still unclear. The crystal structure of AK implied that the amino acid residue T273 interacted with the residue C271 and might play vital roles in keeping AK's activity, substrate synergism and structural stability. The mutations T273G and T273A led to significantly loss of activity, obviously decreased of substrate synergism and structural stability. Furthermore, spectroscopic experiments indicated that mutations T273G and T273A impaired the structure of AK and led them to a partially unfolded state. The inability to fold to the functional state made the mutations prone to aggregate under environmental stresses. Moreover, the mutations T273S and T273D almost had no effects on AK's activity and structural stability. This study herein indicated that the residue T273 played key roles 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, People's Republic of China; Laboratory of Transplantation and Immunology, Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of China.
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, People's Republic of China.
authors.forename: Hua-Yan
authors.initials: HY
authors.lastname: Guo
authors.affiliation: Department of Hematology, the Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of 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, People's Republic of China.
authors.forename: Bian-Mei
authors.initials: BM
authors.lastname: Ru
authors.affiliation: Department of Hematology, the Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of 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, People's Republic of 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, People's Republic of China; Laboratory of Transplantation and Immunology, Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of 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.
authors.forename: Xiao-Yun
authors.initials: XY
authors.lastname: Wang
authors.affiliation: Department of Neurobiology, Xuzhou Medical College, 221002 Xuzhou, People's Republic of China. Electronic address: lifeng1982315@163.com.
authors.forename: Feng
authors.initials: F
authors.lastname: Li
authors.affiliation: Department of Hematology, the Affiliated Hospital of Xuzhou Medical College, No. 99 West Huaihai Road, Xuzhou 221002, People's Republic of China. Electronic address: lihmd@163.com.
authors.forename: Kai-Lin
authors.initials: KL
authors.lastname: Xu
mesh_terms: D000596:Amino Acids / Q000737:chemistry*; D001122:Arginine Kinase / Q000737:chemistry* / Q000235:genetics; D004734:Energy Metabolism; D007700:Kinetics; D009154:Mutation; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity
chemical_list: D000596:Amino Acids; D001122:Arginine Kinase
keywords: 1-anilinonaphtalene-8-sulfonate; AK; ANS; Arginine kinase; CK; E(max); GdnHCl; IPTG; PK; SEC; Structural stability; Substrate synergism; arginine kinase; creatine kinase; emission maximum wavelength of the intrinsic fluorescence.; guanidine hydrochloride; isopropyl-d-thiogalactopyranoside; phosphogen kinase; size exclusion chromatography