Kinetic studies on the thiol protease from <i>Actinidia chinensis</i>

Boland, Michael J.; Hardman, Michael J.

doi:10.1016/0014-5793(72)80641-0

Cited by 67 publications

(52 citation statements)

References 14 publications

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“…Samples (2 g) plus 150 mg polyvinylpolypyrrolidone were homogenized with a Polytron in 6.0 mL of 0.25 M Mes (Na+) buffer (pH as stated for individual experiments), 0.4 M NaC1, 10 mM sodium tetrathionate. The last was added to inhibit the protease, actinidin (Boland and Hardman, 1972). The homogenate was centrifuged (2000g, 10 min) and the supematant was assayed for XET.…”

Section: Extraction and Assay Of Xetmentioning

confidence: 99%

Xyloglucan Endotransglycosylase Activity Increases during Kiwifruit (Actinidia deliciosa) Ripening (Implications for Fruit Softening)

1993

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l h e activity of xyloglucan endotransglycosylase (XET) was assayed in three tissue zones of kiwifruit (Actinidia deliciosa [A.Chev.] C.F. Liang et A.R. Ferguson var deliciosa cv Hayward) at harvest and at severa1 softening stages following a postharvest ethylene treatment. At harvest, extractable XET activity per unit fresh weight in the inner pericarp (IP) and core tissue was 4.5 and 42 times higher, respectively, than in the outer pericarp (OP).Within 24 h of ethylene treatment there was an increase in the adivity and specific activity of XET in all tissues that continued throughout softening. Activity increased most in the OP, where it showed a 12-fold rise 6 d after ethylene treatment compared with 4.5-and 2.5-fold increases in the IP and core tissues, respectively. Visible swelling of the cell wall in each tissue was observed 24 h after the first detectable rise in XET activity and was most pronounced in the OP, which showed the greatest percentage increase in XET activity. Xyloglucan, galactoglucomannan, and cell wall materials isolated and purified from kiwifruit OP were tested as donor substrates for kiwifruit XET. The enzyme showed activity against xyloglucan but was inadive against galadoglucomannan. XET was active against cell wall materials from unripe and ripe fruit, with swollen walls from the latter being the better substrate. l h e results indicate that XET may have a key role early in fruit ripening, loosening the cell wall in preparation for further modification by other cell wall-associated enzymes.

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Section: Extraction and Assay Of Xetmentioning

confidence: 99%

Xyloglucan Endotransglycosylase Activity Increases during Kiwifruit (Actinidia deliciosa) Ripening (Implications for Fruit Softening)

1993

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“…Actinidin activity was measured spectrophotometrically using the assay of Boland and Hardman [3]. Ten ml of extract was assayed in 3 ml of cysteine buffer (0.1 ~o cysteine, pH 6.0), using the artificial substrate N-a-CBZ-l-lysine p-nitrophenyl ester (0.1 M).…”

Section: Measurement Of Cysteine Protease Activity In Kiwifruit Tissuesmentioning

confidence: 99%

Fruit developmental regulation of the kiwifruit actinidin promoter is conserved in transgenic petunia plants

Lin

Burns²,

Gardner

1993

Plant Mol Biol

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We have examined the expression of actinidin, a cysteine protease found in kiwifruit, over the course of fruit development. Protease activity was first seen in fruit that had reached about half their final weight, and rose to high levels at harvest. The 5'-flanking region (nucleotides -1301 to +58) of a kiwifruit actinidin gene was fused to the beta-glucuronidase (GUS)-coding region, and the chimaeric gene was introduced into transgenic petunia plants. Induction of the GUS gene was observed during the later stages of seed pod development, closely resembling the pattern of actinidin induction in fruit tissues of kiwifruit. Some GUS expression was also detected in the vascular system of the receptacle, leaves, stems and roots. A shorter promoter fragment consisting of nucleotides -115 to +58 conferred similar spatial and temporal regulation in some of the transgenic plants.

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“…Actinidin is a well-characterized Cys protease, with a wide pH activity range and wide substrate specificity (McDowall, 1970;Boland and Hardman, 1972) found in the Chinese gooseberry, or kiwifruit (Actinidiu chinensis, and the cultivated hexaploid Actinidia deliciosa). Protein and DNA sequence data show that actinidin is a member of a group of closely related Cys proteases found in plants (e.g.…”

mentioning

confidence: 99%

Correct Processing of the Kiwifruit Protease Actinidin in Transgenic Tobacco Requires the Presence of the C-Terminal Propeptide

et al. 1995

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A 35s cauliflower mosaic virus promoter and a tapetum-specific promoter were used to direct the synthesis in tobacco of preproactinidin and a derivative that lacked a C-terminal extension. Preproactinidin was processed into a form that migrated identically on protein gels with mature actinidin extracted from kiwifruit. This protein was proteolytically active in vitro, and high-leve1 accumulation of this protein appeared to be detrimental to plant growth. Plants expressing an actinidin cDNA construct that lacked the sequence encoding the C-terminal propeptide were phenotypically normal but accumulated N-proactinidin, which was proteolytically active in vitro but did not self-cieave to mature actinidin. In transgenic tobacco, the C-terminal extension of actinidin is therefore required for correct processing.

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Kinetic studies on the thiol protease from Actinidia chinensis

Cited by 67 publications

References 14 publications

Xyloglucan Endotransglycosylase Activity Increases during Kiwifruit (Actinidia deliciosa) Ripening (Implications for Fruit Softening)

Xyloglucan Endotransglycosylase Activity Increases during Kiwifruit (Actinidia deliciosa) Ripening (Implications for Fruit Softening)

Fruit developmental regulation of the kiwifruit actinidin promoter is conserved in transgenic petunia plants

Correct Processing of the Kiwifruit Protease Actinidin in Transgenic Tobacco Requires the Presence of the C-Terminal Propeptide

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