Nucleoside Triphosphatase from the Hen’s Egg White and Vitelline Membrane

Abstract

Hen’s egg white and vitelline membrane nucleoside triphosphatases were purified resulting in active soluble subunits with MR 260,000 ± 10,000. pH optima are divalent cation dependent and situated at pH 6.2 and 8.0 with ATP and at pH 6.15 with ADP as substrate. Ca^2+ and Mg^2+ and K(i) values for are activators. Km Pi and PPi were determined. The enzymes are specific neither for ATP nor for ADP alone. No separation between nucleoside triphosphatase and nucleoside diphosphatase could be achieved. Differences found in their action can be due to differences in organization and properties of the (intermediary) enzyme-substrate complexes. A close relationship exists with homologous enzymes found in oviductal secretory cells and in oviductal secretions.

Phosphorylating-Dephosphorylating Enzymes of Avian Oviductal Secretions

“…Some research has been directed toward the presence of an ATPase that is shed from the surfaces of ovi ductal secretory cells, is present in micellar form in oviductal fluids and is incorporated into the vitelline membrane (1,3,7,8). As shown in this paper, the phosphorylatingdephosphorylating enzymes can be separated by column chromatography from the ATPases and partially separated from one another.…”

Salmonella Enteritidis in shell eggs: Current issues and prospects for control

“…Should this membrane fail, yolk and albumen contents can mix, which causes an influx of iron and other compounds into the albumen and the defenses of the egg are weakened if not destroyed (Burley & Vadehra, 1989). Not only is the vitelline membrane responsible for the segregation of yolk and albumen but also plays a role in allowing the penetration of materials involved in fertilization, yet it must exclude the transfer of nutrient molecules and bacterial cells (Debruyne & Stockx, 1978;Mann, 2008).…”