If the prey is unable to escape, it will continue to stimulate the inner surface of the lobes, and this causes a further growth response that forces the edges of the lobes together, eventually sealing the trap hermetically and forming a 'stomach' in which digestion occurs. Digestion is catalysed by enzymes secreted by glands in the lobes.
Oxidative protein modification is likely to be a predigestive mechanism of the Dionaea muscipula. Aqueous leaf extracts have been found to contain quinones such as the naphthoquinone plumbagin that couples to different NADH-dependent diaphorases to produce superoxide and hydrogen peroxide upon autoxidation.[17] Such oxidative modification could rupture animal cell membranes. Plumbagin is known to induce apoptosis, associated with the regulation of Bcl-2 family of proteins.[18] When the Dionaea extracts were preincubated with diaphorases and NADH in the presence of serum albumin (SA), subsequent tryptic digestion of SA was facilitated.[17] Since the secretory glands of Droseraceae contain proteases and possibly other degradative enzymes, it may be that the presence of oxygen-activating redox cofactors function as extracellular predigestive oxidants to render membrane-bound proteins of the prey (insects) more susceptible to proteolytic attacks.[17]
Digestion takes about ten days, after which the prey is reduced to a husk of chitin. The trap then reopens, and is ready for reuse.[19]
If the prey is unable to escape, it will continue to stimulate the inner surface of the lobes, and this causes a further growth response that forces the edges of the lobes together, eventually sealing the trap hermetically and forming a 'stomach' in which digestion occurs. Digestion is catalysed by enzymes secreted by glands in the lobes.Oxidative protein modification is likely to be a predigestive mechanism of the Dionaea muscipula. Aqueous leaf extracts have been found to contain quinones such as the naphthoquinone plumbagin that couples to different NADH-dependent diaphorases to produce superoxide and hydrogen peroxide upon autoxidation.[17] Such oxidative modification could rupture animal cell membranes. Plumbagin is known to induce apoptosis, associated with the regulation of Bcl-2 family of proteins.[18] When the Dionaea extracts were preincubated with diaphorases and NADH in the presence of serum albumin (SA), subsequent tryptic digestion of SA was facilitated.[17] Since the secretory glands of Droseraceae contain proteases and possibly other degradative enzymes, it may be that the presence of oxygen-activating redox cofactors function as extracellular predigestive oxidants to render membrane-bound proteins of the prey (insects) more susceptible to proteolytic attacks.[17]Digestion takes about ten days, after which the prey is reduced to a husk of chitin. The trap then reopens, and is ready for reuse.[19]
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