Isolation and Characterization of Phenoloxidase from Egg Masses of the Gastropod Mollusc, Biomphalaria glabrata

Purification and characterisation of phenoloxidase from amphioxus Branchiostoma belcheri tsingtauense

“…This is similar to the enzymes from the haemocytes of Penaeus californiensis and Pacifastacus leniusculus, and from the egg masses of Biomphalaria glabrata [22,47,49]. Fig.…”

“…The isolated enzyme was assayed for PO activity in the presence of PO inhibitors PTU and sodium azide [22,43]. A total of 100 ml of the isolated enzyme was added to 1230 ml of 1 mM PTU or 1 mM sodium azide in 10 mM CAC, and pre-incubated at 30 (C for 20 min.…”

“…ProPO can readily be activated to PO by both an endogenous activating system and exogenous activators such as trypsin, lipopolysaccharide and zymosan (b-1,3-glucan) [1,11e14]. It has been shown that the proPO system, comprising proPO together with its activating enzyme, plays a role in defence reactions, including melanisation [15], sclerotisation [16], encapsulation [17e19] and wound healing [20], in both arthropods and molluscs [21,22]. In addition, the proPO system is also involved in several physiological processes such as neurotransmitter synthesis, eye pigmentation and production of inks [23e26].…”

Purification and characterization of phenoloxidase from clam Ruditapes philippinarum

“…POs from several invertebrates have been successfully purified and characterized. Their molecular masses are highly variable, ranging from 250 kDa in Heliothis virescens [11] to 35 kDa in snail (Biomphalaria glabrata) [12], with a frequent range of 60e80 kDa [13]. Accurate determination of the molecular size of PO and proPO has been cumbersome due to the molecular aggregation and stickiness of these proteins [11,14].…”

Presence of prophenoloxidase in the humoral fluid of amphioxus Branchiostoma belcheri tsingtauense

“…It is highly likely that proPO in amphioxus humoral fluid consists of a 72 kDa polypeptide and a second polypeptide of either 46 or 44 kDa. However, it is of interest to note that different molecular masses have been reported in invertebrate proPOs: 37e49 kDa in Procambarus clarkii [44], 35 kDa in Biomphalaria glabrata [51] and 70e80 kDa in Bombyx mori [52], Manduca sexta [53], Blaberus discoidalis [54], Galleria mellonella [13] and Holotrichia diomphilia [55]. Whether the smaller size of the enzyme PO in amphioxus humoral fluid is due to species difference or proteolytic cleavage needs further study.…”