Preparation of inside-out membrane vesicles from neutrophils capable of actively transporting calcium
Volpi, M.; Naccache, P.H.; Sha'afi, R.I.
Biochemical and Biophysical Research Communications 106(1): 123-130
1982
ISSN/ISBN: 0006-291X PMID: 7103976 Document Number: 186738
Inside-out membrane vesicles were prepared from rabbit neutrophils. These vesicles are capable of actively transporting Ca. This active transport requires the presence of MgATP. Other nucleotides such as UTP, GTP, CTP, AMP and ADP are not able to stimulate the active uptake of Ca in these vesicles. This transport system has a Km for free Ca of 1.3 .+-. 0.7 .mu.M and a Vmax of 3.6 .+-. 0.5 nmol/mg protein per min and is inhibited by the calmodulin inhibitor, trifluoperazine.