The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnet...The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field.A highly conserved ironsulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor(MagR).Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception.In the current study,we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons,an avian species that relies on the geomagnetic field for navigation and homing.Pigeon MagR showed significantly higher total iron content from both iron-and ironsulfur binding.Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding,and its mutation abolished iron-binding capacity of the protein.Surprisingly,both iron binding and iron-sulfur binding demonstrated synergistic effects,and thus appear to be integral and indispensable to pigeon MagR magnetism.These results not only extend our current understanding of the origin and complexity of MagR magnetism,but also imply a possible molecular explanation for the huge diversity in animal magnetoreception.展开更多
Background: Anemia is one of the complications of chronic kidney disease (CKD) which necessitates multiple blood transfusions. These multiple transfusions are usually accompanied by Iron over load. The current study a...Background: Anemia is one of the complications of chronic kidney disease (CKD) which necessitates multiple blood transfusions. These multiple transfusions are usually accompanied by Iron over load. The current study aimed to assess the Iron profile in Sudanese patients with chronic renal failure received regular blood transfused. Materials and Methods: A descriptive analytical case control study was performed in Alturki Teaching Hospital, Khartoum, Sudan. A total of 90 Sudanese were enrolled in this study (30 CKD patients under hemodialysis and undergo multiple blood transfusion, 30 CKD patients under hemodialysis but not blood transfusion and 30 healthy controls, 51 (57%) were male and 39 (43%) were females, their age ranged between 28 to 75 years. Iron profile (serum iron, serum ferritin and total iron binding capacity (TIBC)) were measured using full automated Chemical analyzer Mindray BS 200 (China). Data were analyzed by using statistical package for social sciences (SPSS) verssion16. Results: The present study showed that serum iron and serum ferritin of those under hemodialysis and received regular blood transfusion patient were significantly higher compared to those under hemodialysis and did not received regular blood transfusion patients (P value 0.000 and 0.01) respectively. Conclusion: Patients with chronic renal failure and under hemodialysis and receive regular and multiple transfusions are prone to iron overload.展开更多
An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor.This preparation could chelate Fe3+and reduce Fe3...An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor.This preparation could chelate Fe3+and reduce Fe3+to Fe2+,demonstrating that the substance may serve as a ferric chelator,oxygen-reducing agent,and redox-cycling molecule,which would include functioning as the electron transport carrier in Fenton reaction.Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR,13C-NMR,difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation.The results indicated that the iron-binding chelator could destroy theβ-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups.The low-molecular-weight chelator secreted by C.versicolor resulted in new phenolic substructures in the lignin polymer,making it susceptible to attack by laccase or manganese peroxidase.Thus,the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more acces-sible to degradation.展开更多
基金supported by the National Natural Science Foundation of China(31640001 to C.X.,U21A20148 to X.Z.and C.X.)the Presidential Foundation of Hefei Institutes of Physical Science,Chinese Academy of Sciences(Y96XC11131,E26CCG27,and E26CCD15 to C.X.)。
文摘The ability to navigate long distances is essential for many animals to locate shelter,food,and breeding grounds.Magnetic sense has evolved in various migratory and homing species to orient them based on the geomagnetic field.A highly conserved ironsulfur cluster assembly protein IscA is proposed as an animal magnetoreceptor(MagR).Iron-sulfur cluster binding is also suggested to play an essential role in MagR magnetism and is thus critical in animal magnetoreception.In the current study,we provide evidence for distinct iron binding and iron-sulfur cluster binding in MagR in pigeons,an avian species that relies on the geomagnetic field for navigation and homing.Pigeon MagR showed significantly higher total iron content from both iron-and ironsulfur binding.Y65 in pigeon MagR was shown to directly mediate mononuclear iron binding,and its mutation abolished iron-binding capacity of the protein.Surprisingly,both iron binding and iron-sulfur binding demonstrated synergistic effects,and thus appear to be integral and indispensable to pigeon MagR magnetism.These results not only extend our current understanding of the origin and complexity of MagR magnetism,but also imply a possible molecular explanation for the huge diversity in animal magnetoreception.
文摘Background: Anemia is one of the complications of chronic kidney disease (CKD) which necessitates multiple blood transfusions. These multiple transfusions are usually accompanied by Iron over load. The current study aimed to assess the Iron profile in Sudanese patients with chronic renal failure received regular blood transfused. Materials and Methods: A descriptive analytical case control study was performed in Alturki Teaching Hospital, Khartoum, Sudan. A total of 90 Sudanese were enrolled in this study (30 CKD patients under hemodialysis and undergo multiple blood transfusion, 30 CKD patients under hemodialysis but not blood transfusion and 30 healthy controls, 51 (57%) were male and 39 (43%) were females, their age ranged between 28 to 75 years. Iron profile (serum iron, serum ferritin and total iron binding capacity (TIBC)) were measured using full automated Chemical analyzer Mindray BS 200 (China). Data were analyzed by using statistical package for social sciences (SPSS) verssion16. Results: The present study showed that serum iron and serum ferritin of those under hemodialysis and received regular blood transfusion patient were significantly higher compared to those under hemodialysis and did not received regular blood transfusion patients (P value 0.000 and 0.01) respectively. Conclusion: Patients with chronic renal failure and under hemodialysis and receive regular and multiple transfusions are prone to iron overload.
基金Supported by the National Natural Science Foundation of China(Grant Nos.30170027 and 30371136)
文摘An ultrafiltered low-molecular-weight preparation of chelating compounds was isolated from a wood-containing culture of the white-rot basidiomycete Coriolus versicolor.This preparation could chelate Fe3+and reduce Fe3+to Fe2+,demonstrating that the substance may serve as a ferric chelator,oxygen-reducing agent,and redox-cycling molecule,which would include functioning as the electron transport carrier in Fenton reaction.Lignin was treated with the iron-binding chelator and the changes in structure were investigated by 1H-NMR,13C-NMR,difference spectrum caused by ionization under alkaline conditions and nitrobenzene oxidation.The results indicated that the iron-binding chelator could destroy theβ-O-4 bonds in etherified lignin units and insert phenolic hydroxyl groups.The low-molecular-weight chelator secreted by C.versicolor resulted in new phenolic substructures in the lignin polymer,making it susceptible to attack by laccase or manganese peroxidase.Thus,the synergic action of the iron-binding chelator and the lignocellulolytic enzymes made the substrate more acces-sible to degradation.
