Abstract
The tools of plant biotechnology that have been developed to improve agronomic traits are now being applied to generate recombinant protein products for the food, feed, and pharmaceutical industry. This study addresses several processing and protein recovery issues that are relevant to utilizing transgenic corn as a protein production system. The gus gene coding for beta-glucuronidase (rGUS) was stably integrated and expressed over four generations. The accumulation level of rGUS reached 0.4% of total extractable protein. Within the kernel, rGUS was preferentially accumulated in the germ even though a constitutive ubiquitin promoter was used to direct gus expression. Fourth-generation transgenic seed was used to investigate the effect of seed processing on the activity and the recovery of rGUS. Transgenic seed containing rGUS could be stored at an ambient temperature for up to two weeks and for at least three months at 10 degrees C without a significant loss of enzyme activity. rGUS exposed to dry heat was more stable in ground than in whole kernels. The enzyme stability was correlated with the moisture loss of the samples during the heating. Transgenic seed was dry-milled, fractionated, and hexane extracted to produce full-fat and defatted germ fractions. The results of the aqueous extraction of rGUS from ground kernels, full-fat germ, and defatted-germ samples revealed that approximately 10 times more rGUS per gram of solids could be extracted from the ground full-fat germ and defatted-germ than from the kernel samples. The extraction of corn oil from ground germ with hot hexane (60 degrees C) did not affect the extractable rGUS activity. rGUS was purified from ground kernels and full-fat germ extracts by ion exchange, hydrophobic interaction, and size exclusion chromatography. Similar purity and yield of rGUS were obtained from both extracts. Biochemical properties of rGUS purified from transgenic corn seed were similar to those of E. coli GUS.
Abstract from the paper’s OpenAlex record, shown for indexing and research. Copyright remains with the authors or the publisher. Read at the source ↗
The text the model read, with the source record’s inline markup (italics, sub- and superscripts) rendered and its character entities decoded; quote offsets refer to the raw text.
Claims 12
Claim · model-written summary
The gus gene remained integrated and expressed across four generations.
- Taxon
- corn
Zea mays subsp. mayst0 - Gene
- guse0
- Outcome
- stably integrated and expressed over four generationse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The gus gene coding for beta-glucuronidase (rGUS) was stably integrated and expressed over four generations”
t0“transgenic corn seed”
Claim · model-written summary
rGUS accumulated to 0.4% of extractable protein.
- Taxon
- cornZea mays subsp. mayst0
- Gene
- rGUSe0
- Outcome
- accumulation level of rGUSe0
- Value
- 0.4%e0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The accumulation level of rGUS reached 0.4% of total extractable protein”
t0“transgenic corn seed”
Claim · model-written summary
rGUS preferentially accumulated in the germ.
- Taxon
- cornZea mays subsp. mayst0
- Organ / stage
- germe0
- Gene
- rGUSe0
- Outcome
- preferentially accumulated in the germe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Within the kernel, rGUS was preferentially accumulated in the germ even though a constitutive ubiquitin promoter was used to direct gus expression”
t0“transgenic corn seed”
Claim · model-written summary
Ambient storage for two weeks caused no significant loss of rGUS activity.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- ambient temperature for up to two weekse0
- Outcome
- enzyme activitye0
- Direction
- without a significant losse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic seed containing rGUS could be stored at an ambient temperature for up to two weeks and for at least three months at 10 degrees C without a significant loss of enzyme activity”
t0“transgenic corn seed”
Claim · model-written summary
Storage at 10 degrees C for at least three months caused no significant loss of rGUS activity.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- at least three months at 10 degrees Ce0
- Outcome
- enzyme activitye0
- Direction
- without a significant losse0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Transgenic seed containing rGUS could be stored at an ambient temperature for up to two weeks and for at least three months at 10 degrees C without a significant loss of enzyme activity”
t0“transgenic corn seed”
Claim · model-written summary
Under dry heat, ground kernels retained rGUS stability better than whole kernels.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- dry heate0
- Outcome
- rGUS exposed to dry heat was more stablee0
- Direction
- more stablee0
- Comparator
- whole kernelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rGUS exposed to dry heat was more stable in ground than in whole kernels”
t0“transgenic corn seed”
Claim · model-written summary
Enzyme stability was correlated with sample moisture loss during heating.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- heatinge0
- Outcome
- enzyme stabilitye0
- Qualifier
- moisture loss of the samplese0
Not reportedDirection
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The enzyme stability was correlated with the moisture loss of the samples during the heating”
t0“transgenic corn seed”
Claim · model-written summary
Ground full-fat germ yielded approximately ten times more extractable rGUS per gram than kernels.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- ground full-fat germe0
- Outcome
- rGUS per gram of solidse0
- Direction
- moree0
- Value
- approximately 10 timese0
- Comparator
- kernel samplese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“approximately 10 times more rGUS per gram of solids could be extracted from the ground full-fat germ and defatted-germ than from the kernel samples”
t0“transgenic corn seed”
Claim · model-written summary
Defatted germ yielded approximately ten times more extractable rGUS per gram than kernels.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- defatted-germe0
- Outcome
- rGUS per gram of solidse0
- Direction
- moree0
- Value
- approximately 10 timese0
- Comparator
- kernel samplese0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“approximately 10 times more rGUS per gram of solids could be extracted from the ground full-fat germ and defatted-germ than from the kernel samples”
t0“transgenic corn seed”
Claim · model-written summary
Hot hexane oil extraction did not affect extractable rGUS activity.
- Taxon
- cornZea mays subsp. mayse0
- Treatment
- hot hexane (60 degrees C)e0
- Outcome
- extractable rGUS activitye0
- Direction
- did not affecte0
Not reportedComparator
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“The extraction of corn oil from ground germ with hot hexane (60 degrees C) did not affect the extractable rGUS activity”
Claim · model-written summary
Ground kernels and full-fat germ extracts gave similar rGUS purity and yield.
- Taxon
- cornZea mays subsp. mayst0
- Treatment
- full-fat germ extractse0
- Outcome
- purity and yield of rGUSe0
- Direction
- Similare0
- Comparator
- ground kernelse0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“rGUS was purified from ground kernels and full-fat germ extracts by ion exchange, hydrophobic interaction, and size exclusion chromatography. Similar purity and yield of rGUS were obtained from both extracts”
t0“transgenic corn seed”
Claim · model-written summary
Corn seed rGUS had biochemical properties similar to E. coli GUS.
- Taxon
- cornZea mays subsp. mayse0
- Gene
- rGUSe0
- Outcome
- Biochemical properties of rGUSe0
- Comparator
- E. coli GUSe0
Organisms pictured · Representative pictures of the matched species, not figures from the paper.
Verbatim
e0“Biochemical properties of rGUS purified from transgenic corn seed were similar to those of E. coli GUS”
The same questions in other papers
botanical · yield · Zea mays (maize)Results differ
6 papers in the same direction as this paper · 118 in the opposite direction
- positive
- positive
- positive
121 papers more in this group
See all 125 papers →Claims are grouped by organism, treatment and what was measured or targeted. A paper counts as positive when any of its claims in the group is positive.