Effects of free Ca2+ on the [Ca2+ + Mg2+]-dependent adenosinetriphosphatase (ATPase) of Alzheimer and normal fibroblasts

E Rizopoulos; J P Chambers; M J Wayner; A O Martinez; L S Armstrong

doi:10.1016/0197-4580(89)90008-0

Effects of free Ca2+ on the [Ca2+ + Mg2+]-dependent adenosinetriphosphatase (ATPase) of Alzheimer and normal fibroblasts

Neurobiol Aging. 1989 Nov-Dec;10(6):717-20. doi: 10.1016/0197-4580(89)90008-0.

Authors

E Rizopoulos¹, J P Chambers, M J Wayner, A O Martinez, L S Armstrong

Affiliation

¹ Brain Research Laboratory of Biochemistry, University of Texas, San Antonio 78285.

PMID: 2534159
DOI: 10.1016/0197-4580(89)90008-0

Abstract

Differences between Alzheimer and control fibroblast [Ca2+ + Mg2+]-dependent ATPase activity at free Ca2+ concentration considerably higher than physiologic concentrations were observed. At 50 microM free Ca2+, Alzheimer and control fibroblast homogenates exhibited maximum velocity values ranging from 8 to 25 nmoles phosphate released/min/mg protein. Higher free Ca2+ (350 microM) inhibited control fibroblast ATPase activity approximately 77%; whereas, Alzheimer fibroblasts retained greater than 75% starting activity. Although the pathophysiological significance of these findings is at present unclear, these data suggest the Ca2+ pump of Alzheimer fibroblasts behaves differently in the presence of high free Ca2+. Such behavior may be of potential diagnostic value.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Alzheimer Disease / enzymology*
Ca(2+) Mg(2+)-ATPase / antagonists & inhibitors*
Calcium / pharmacology*
Calcium-Transporting ATPases / antagonists & inhibitors*
Cell Line
Fibroblasts / enzymology
Humans

Substances

Ca(2+) Mg(2+)-ATPase
Calcium-Transporting ATPases
Calcium