TY - JOUR
T1 - Cooperativity among manganese-binding sites in the H+-ATPase of chloroplasts.
AU - Hiller, R.
AU - Carmeli, C.
PY - 1985/2/10
Y1 - 1985/2/10
N2 - Coupling factor, isolated from lettuce chloroplasts, contained several binding sites for Mn2+ ions. Three of these sites showed strong cooperative interactions having a Hill coefficient of 2.9 +/- 0.20 and a Kd of 14.7 +/- 0.44 microM. Three additional non-interacting Mn2+-binding sites were found with a Kd of 46.7 +/- 2.3 microM. Chemical modification with naphthylglyoxal of 1 arginyl residue/chloroplast coupling factor 1, which inhibited ATPase activity, inhibited the cooperativity among the sites but did not prevent Mn2+ binding to the enzyme. It is suggested that the cooperative interaction among the Mn2+-binding sites is an expression of the interaction among the active sites of the enzyme which is required for catalysis.
AB - Coupling factor, isolated from lettuce chloroplasts, contained several binding sites for Mn2+ ions. Three of these sites showed strong cooperative interactions having a Hill coefficient of 2.9 +/- 0.20 and a Kd of 14.7 +/- 0.44 microM. Three additional non-interacting Mn2+-binding sites were found with a Kd of 46.7 +/- 2.3 microM. Chemical modification with naphthylglyoxal of 1 arginyl residue/chloroplast coupling factor 1, which inhibited ATPase activity, inhibited the cooperativity among the sites but did not prevent Mn2+ binding to the enzyme. It is suggested that the cooperative interaction among the Mn2+-binding sites is an expression of the interaction among the active sites of the enzyme which is required for catalysis.
UR - http://www.scopus.com/inward/record.url?scp=0022422501&partnerID=8YFLogxK
U2 - 10.1016/s0021-9258(18)89638-7
DO - 10.1016/s0021-9258(18)89638-7
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AN - SCOPUS:0022422501
SN - 0021-9258
VL - 260
SP - 1614
EP - 1617
JO - The Journal of biological chemistry
JF - The Journal of biological chemistry
IS - 3
ER -