Invertase Inhibitor from Potatoes: Purification, Characterization, and Reactivity with Plant Invertases

Pressey, Russell

doi:10.1104/pp.42.12.1780

Cited by 100 publications

(56 citation statements)

References 12 publications

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“…To date, the only valid test for the presence of the endogenous inhibitor is "foaming" (9,13,17). The inhibitor, which is probably a protein (14), can be selectively inactivated through surface denaturation if conditions of foaming are carefully controlled (9). The foaming procedure did not seem adaptable to the whole disk method of assay; furthermore, we did not know what effect the ethyl acetate treatment would have on the inhibitor.…”

mentioning

confidence: 99%

“…The increased activity may be the result of de novo synthesis of invertase inasmuch as it is inhibited by chemicals that interfere with RNA or protein synthesis (3, 7, 23) and the buoyant density of an invertase fraction from carrot disks was increased by incubation in deuterium oxide (24). On the other hand, Pressey has demonstrated the presence of an endogenous invertase inhibitor in potatoes (13,14), red and sugar beets (15), and sweet potatoes (15). He pointed out (15) that there might be an inactivation of the inhibitor after slicing which could account for at least part of the increase in invertase activity.…”

Section: Introductionmentioning

confidence: 99%

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Changes in Potato Tuber Invertase and Its Endogenous Inhibitor After Slicing, Including a Study of Assay Methods

Ewing

Devlin²,

McNeill³

et al. 1977

Plant Physiol.

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The increase in the invertase activity of extracts from freshly cut potato (Solanum tluberosum L.) by "foaming," caused by selective denaturation of an endogenous invertase inhibitor, did not occur in extracts made from thin disks 2 days after slicing. Rather, foaming such extracts decreased invertase activity. Apparendy, the inhibitor disappeared after slicing, and the enzyme became more labile to foaming. Such disappearance of inhibitor could account for up to 15% of the dramatic increase in total invertase activity that had occurred within 2 days after slicing. The difference between extracts from 0-day and 2-day slices was mainly in the first of two peaks of invertase activity eluted from diethylaminoethyl-cellulose columns. This peak was increased by foaming 0-day extracts, but even when foamed was much smaller than in 2-day extracts. The apparent loss in inhibitor was not caused by a decreasing susceptibility of the enzyme to the inhibitor. Both the increase in total invertase activity and the apparent loss of inhibitor after slicing were partially blocked by actinomycin D and completely blocked by cydoheximide.The presence of the inhibitor can lead to serious errors in the usual whole disk method of assay for invertase in slices. Ethyl acetate treatment reduces the solubility of the enzyme but does not inactivate the inhibitor.Slices of storage tissue undergo manifold metabolic changes if kept moist and well aerated after cutting. Among these is a dramatic increase in invertase activity (1,7,21,22). The increased activity may be the result of de novo synthesis of invertase inasmuch as it is inhibited by chemicals that interfere with RNA or protein synthesis (3, 7, 23) and the buoyant density of an invertase fraction from carrot disks was increased by incubation in deuterium oxide (24). On the other hand, Pressey has demonstrated the presence of an endogenous invertase inhibitor in potatoes (13,14), red and sugar beets (15), and sweet potatoes (15). He pointed out (15) that there might be an inactivation of the inhibitor after slicing which could account for at least part of the increase in invertase activity.We wanted to investigate Pressey's suggestion but found it necessary first to consider the effects of various assay procedures on the apparent activity of the enzyme and inhibitor. The most A serious drawback to the whole disk method of assay is the difficulty of estimating how much the inhibitor is reducing the total invertase activity. To date, the only valid test for the presence of the endogenous inhibitor is "foaming" (9, 13, 17). The inhibitor, which is probably a protein (14), can be selectively inactivated through surface denaturation if conditions of foaming are carefully controlled (9). The foaming procedure did not seem adaptable to the whole disk method of assay; furthermore, we did not know what effect the ethyl acetate treatment would have on the inhibitor. The procedures used in previous inhibitor studies (13,17), namely homogenization of the tissue and assay of the soluble inve...

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confidence: 99%

Section: Introductionmentioning

confidence: 99%

Changes in Potato Tuber Invertase and Its Endogenous Inhibitor After Slicing, Including a Study of Assay Methods

Ewing

Devlin²,

McNeill³

et al. 1977

Plant Physiol.

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“…Invertase inhibitors have been known for a long time [20,21], but have only recently been cloned [17] and characterized [22,23]. Functional genomics approaches revealed that invertase inhibitors and inhibitors of pectin methylesterase (PMEI) [24] belong to the same diverse protein family.…”

Section: Introductionmentioning

confidence: 99%

In Arabidopsis thaliana, the invertase inhibitors AtC/VIF1 and 2 exhibit distinct target enzyme specificities and expression profiles

2004

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Plant cell wall (CWI) and vacuolar invertases (VI) play important roles in carbohydrate metabolism, stress responses and sugar signaling. Addressing the regulation of invertase activities by inhibitor proteins (C/VIF, cell wall/ vacuolar inhibitor of fructosidase), we have identified two C/ VIFs from Arabidopsis thaliana. AtC/VIF1 showed specific inhibition of VI activity, whereas AtC/VIF2 inhibited both, CWI and VI. Expression analysis revealed that expression of AtC/ VIF1 was restricted to specific organs, AtC/VIF2, however, was weakly expressed throughout plant development. Promoter::GUS transformants confirmed pronounced differences of tissue/cell type-specific expression between both isoforms. Growth of an AtC/VIF1 T-DNA KO mutant was unaffected, but VI activity and hexose content were slightly increased.

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“…This inhibitor is effective for not only potato tuber invertase but also many other plant invertases with pH optima near 4.5 (5). The wide reactivity of the potato inhibitor indicates similarities in invertases from diverse plant sources.…”

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confidence: 99%

“…The first proteininhibitor of invertase was isolated from potato tubers (3,5). This inhibitor is effective for not only potato tuber invertase but also many other plant invertases with pH optima near 4.5 (5).…”

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Invertase Inhibitors From Red Beet, Sugar Beet, and Sweet Potato Roots

Pressey¹

1968

Plant Physiol.

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Invertase Inhibitor from Potatoes: Purification, Characterization, and Reactivity with Plant Invertases

Cited by 100 publications

References 12 publications

Changes in Potato Tuber Invertase and Its Endogenous Inhibitor After Slicing, Including a Study of Assay Methods

Changes in Potato Tuber Invertase and Its Endogenous Inhibitor After Slicing, Including a Study of Assay Methods

In Arabidopsis thaliana, the invertase inhibitors AtC/VIF1 and 2 exhibit distinct target enzyme specificities and expression profiles

Invertase Inhibitors From Red Beet, Sugar Beet, and Sweet Potato Roots

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