TY - JOUR
T1 - The cause of superstoichiometric CA2+ uptake and H+ ejection in L1210 mouse ascites tumor mitochondria
AU - Reynafarje, Baltazar
AU - Lehninger, Albert L.
PY - 1974/3/15
Y1 - 1974/3/15
N2 - Mitochondria from L1210 mouse leukemia cells show superstoichiometric → H+/2e- ejection and → Ca2+/2e- uptake ratios in the absence of phosphate. Kinetic analysis of Ca2+-induced respiratory jumps shows a very rapid, early burst of H+ ejection and Ca2+ uptake dependent on energy-coupled electron transport but with extraordinarily high stoichiometry (→H+/2e- > 20; →Ca2+/2e- > 10), followed by a slower phase with normal stoichiometry (→H+/2e-=4-5; →Ca2+/2e-=4.0). The early burst of H+ ejection, which has a higher KM for Ca2+ than respiratory stimulation, accounts for the superstoichiometry phenomenon; it requires energization by state 4 respiration.
AB - Mitochondria from L1210 mouse leukemia cells show superstoichiometric → H+/2e- ejection and → Ca2+/2e- uptake ratios in the absence of phosphate. Kinetic analysis of Ca2+-induced respiratory jumps shows a very rapid, early burst of H+ ejection and Ca2+ uptake dependent on energy-coupled electron transport but with extraordinarily high stoichiometry (→H+/2e- > 20; →Ca2+/2e- > 10), followed by a slower phase with normal stoichiometry (→H+/2e-=4-5; →Ca2+/2e-=4.0). The early burst of H+ ejection, which has a higher KM for Ca2+ than respiratory stimulation, accounts for the superstoichiometry phenomenon; it requires energization by state 4 respiration.
UR - http://www.scopus.com/inward/record.url?scp=0015944673&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0015944673&partnerID=8YFLogxK
U2 - 10.1016/S0006-291X(74)80388-8
DO - 10.1016/S0006-291X(74)80388-8
M3 - Article
C2 - 4828189
AN - SCOPUS:0015944673
VL - 57
SP - 286
EP - 292
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
SN - 0006-291X
IS - 1
ER -