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S Ji

Publications and source records attributed to S Ji.

115 records · Page 7Linked to original sources
PubMed1973

Transductional and structural principles of the mitochondrial transducing unit.

The electromechanochemical model has been reformulated to take account of the close connection between energy coupling and catalysis. In catalysis the protein is programmed to utilize thermal energy to produce local strains in the catalytic cavity and to generate conformational states that favor substrate --> product conversion. Energy coupling involves transfer of vibrational energy through the protein. Underlying these two energy transductional maneuvers is the concept of a pulsating protein capable of redistributing electromechanochemical potential energy in a programmed fashion. The mitochondrial supermolecule has been defined, and it has been shown how the supermolecule concept rationalizes the coupling options, the stoichiometry of the coupling complexes, and the multistep character of electron transfer.

Adenosine Triphosphate↗
PubMed1972

Electromechanochemical model of mitochondrial structure and function.

A NEW MODEL OF MITOCHONDRIAL STRUCTURE AND FUNCTION IS PROPOSED ON THE BASIS OF FOUR FUNDAMENTAL ASSUMPTIONS: (a) electrons and protons are separated in the electron transfer complexes; (b) the ATPase undergoes conformational state-transitions induced by an electric field; (c) energy is transferred by an electric field effect; and (d) a conformationally strained protein system can be relaxed via a bond-forming chemical reaction. The model can explain all of the mitochondrial coupled processes and, in addition, it provides a reasonable rationalization of the correlation between mitochondrial structure and function.

Biological Transport, Active↗
PubMedDate not supplied

Disturbances of extracellular pK, pNa and pH during no-flow anoxia.

The initial period of no-flow anoxia can be divided in at least two parts. During the first period lasting approximately 1 min., the O2 available in tissue gives rise to CO2 which increases hydrogen ion activity and may lead to Na+ influx2 (presumably due to increased membrane permeability to Na+). In the second period, starting after the first minute, the increase in lactate content leads to further decrease in pH and is accompanied by extensive sodium influx and a distinct potassium efflux. However, it is striking that the isolated perfused rat liver is able to tolerate 1 hour of norm-flow anoxia without severe cellular damage, whereas two minutes of no-flow anoxia lead to a decrease in cellular ATP content by 28%.

Adenosine Triphosphate↗