A New Way to Identify G/C/T Children: The Anecdotal Approach

Miller, Pamela S.; Ford, Barbara

doi:10.1177/107621758300300504

Cited by 4 publications

(4 citation statements)

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“…8B) by acting as an aminoendopeptidase. However, PepN is not essential in E. coli (61), probably due to the presence of redundant peptidases (62). In fact, mutations in all four peptidases (PepN, PepA, PepB, and PepD), but not single peptidase genes, in Salmonella typhimurium result in a significant decrease in cytosolic protein degradation (63).…”

Section: Discussionmentioning

confidence: 99%

PepN, the Major Suc-LLVY-AMC-hydrolyzing Enzyme inEscherichia coli, Displays Functional Similarity with Downstream Processing Enzymes in Archaea and Eukarya

Chandu

Kumar

Nandi

2003

Journal of Biological Chemistry

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Succinyl-Leu-Leu-Val-Tyr-7-amido-4-methylcoumarin (Suc-LLVY-AMC), a fluorogenic endopeptidase substrate, is used to detect 20 S proteasomal activity from Archaea to mammals. An o-phenanthroline-sensitive Suc-LLVY-AMC hydrolyzing activity was detected in Escherichia coli although it lacks 20 S proteasomes. We identified PepN, previously characterized as the sole alanine aminopeptidase in E. coli, to be responsible for the hydrolysis of Suc-LLVY-AMC. PepN is an aminoendopeptidase. First, extracts from an ethyl methanesulfonate-derived PepN mutant, 9218, did not cleave Suc-LLVY-AMC and L-Ala-para-nitroanilide (pNA). Second, biochemically purified PepN cleaves a wide variety of both aminopeptidase and endopeptidase substrates, and L-Ala-pNA is cleaved more efficiently than other substrates. Studies with bestatin, an aminopeptidasespecific inhibitor, suggest differences in the mechanisms of cleavage of aminopeptidase and endopeptidase substrates. Third, PepN hydrolyzes whole proteins, casein and albumin. Finally, an E. coli strain with a targeted deletion in PepN also lacks the ability to cleave Suc-LLVY-AMC and L-Ala-pNA, and expression of wild type PepN in this mutant rescues both activities. In addition, we identified a low molecular weight Suc-LLVY-AMC-cleaving peptidase in Mycobacterium smegmatis, a eubacteria harboring 20 S proteasomes, to be an aminopeptidase homologous to E. coli PepN, by mass spectrometry analysis. "Sequence-based homologues" of PepN include well characterized aminopeptidases, e.g. Tricorn interacting factors F2 and F3 in Archaea and puromycin-sensitive aminopeptidase in mammals. However, our results suggest that eubacterial PepN and its homologues displaying aminoendopeptidase activities may be "functionally similar" to enzymes important in downstream processing of proteins in the cytosol: Tricorn-F1-F2-F3 complex in Archaea and TPPII/Multicorn in eukaryotes.Dynamic changes in the proteome of a cell depend on rates of protein synthesis and their degradation. The past few decades have witnessed enormous strides in identifying the molecules and understanding the mechanisms involved in intracellular protein degradation. There is increasing evidence of the involvement of protein degradation in diverse biological activities, e.g. cell cycle progression, transcriptional activation, antigen processing, disease progression, etc. (1-5).Broadly, cytosolic protein degradation is categorized into four steps. (i) Proteins targeted for degradation are initially unfolded into polypeptides by ATP-dependent proteases belonging to the Lon/Clp family in bacteria or 26 S proteasomes in higher organisms (1-5). (ii) These enzymes also make the initial endoproteolytic "cuts" in the polypeptide. Interestingly, in both Escherichia coli (6) and higher organisms (7) the average length of peptides released by these enzymes range from 3 to 25 amino acids. (iii) These longer peptides are trimmed into smaller peptides (less than 10 amino acids) by the action of endopeptidases (8 -11), tripeptidyl-and dipeptidylpeptidases...

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Section: Discussionmentioning

confidence: 99%

PepN, the Major Suc-LLVY-AMC-hydrolyzing Enzyme inEscherichia coli, Displays Functional Similarity with Downstream Processing Enzymes in Archaea and Eukarya

Chandu

Kumar

Nandi

2003

Journal of Biological Chemistry

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“…A minimum flux of 10 lg/cm 2 /day is necessary to ensure AF properties. 24,25 Our final goal is to release SeaNine 211 at a flux higher than this threshold value for the largest possible number of days. For a coating, having a 100-lm thickness containing 10% Seanine 211 (average thickness and loading of our coatings), a 1 cm 2 section contains 10 mg of SeaNine 211.…”

Section: Release Of Seanine 211 From the Coatingmentioning

confidence: 99%

Transparent antifouling coatings via nanoencapsulation of a biocide

Zhang

Cabane

Claverie

2007

J of Applied Polymer Sci

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Transparent coatings releasing an antifouling agent (AF) can be used to reduce the marine fouling of optical lenses. A variety of water-borne coatings based on poly(methyl methacrylate-co-butyl acrylate) (PMMAco-PBA) were synthesized using a two-stage miniemulsion process. During this process, the AF, SeaNine 211, was nanoencapsulated in domains small enough not to scatter light. The release rate of SeaNine 211 was studied for the polymers of different T g , and found to be sufficient to impart AF properties. However, over time, the coatings were found to develop a whitish aspect (blushing) due to water retrodiffusion.

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“…However, this has not been all positive as many insect pests have developed resistances to major classes of synthetic insecticides, and serious damage to human health, agriculture, and natural ecosystems has been attributed to the continuing application of synthetic pesticides. In addition, because insecticides and herbicides are sprayed or spread across entire agricultural fields, it has been estimated that over 98% of sprayed insecticides and 95% of herbicides reach destinations other than their target species, often resulting in harm to non-target wildlife and the environment 6 . Recent estimates have even suggested that pesticides are responsible for more than 20,000 human fatalities, yearly, primarily in developing countries 7 .…”

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confidence: 99%

A Floral Fragrance, Methyl Benzoate, is An Efficient Green Pesticide

Yan

Zhang

2017

Sci Rep

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Over-reliance on synthetic pesticides in insect pest control has caused widespread public and scientific concerns for human health and the environment, especially since many insect pests have already developed resistances to conventional pesticides and Bt products. For this reason, there is a considerable interest in development of alternative control methods for insect pest management. Based on laboratory studies, we report that methyl benzoate (MB), a naturally-occurring compound in many plants, may possess toxicity against various stages of a variety of insect pests, including the brown marmorated stinkbug, Halyomorpha halys, diamondback moth, Plutella xylostella, and tobacco hornworm, Manduca sexta, as well as the spotted wing drosophila, Drosophila suzukii. Based on our laboratory toxicity data, MB was at least 5 to 20 times more toxic than the conventional pyrethroid (β-cyfluthrin), sulfur & pyrethrin mixture, and some organic commercial products available on the market against H. halys, P. xylostella, and M. sexta, eggs. Because MB is considered an environment-friendly, it has great potential to be used as an alternative tool to synthetic pesticide for insect pest management in crop production, thereby, reducing threats to natural ecosystems and human health caused by over-application of conventional synthetic pesticides.

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A New Way to Identify G/C/T Children: The Anecdotal Approach

Cited by 4 publications

References 0 publications

PepN, the Major Suc-LLVY-AMC-hydrolyzing Enzyme inEscherichia coli, Displays Functional Similarity with Downstream Processing Enzymes in Archaea and Eukarya

PepN, the Major Suc-LLVY-AMC-hydrolyzing Enzyme inEscherichia coli, Displays Functional Similarity with Downstream Processing Enzymes in Archaea and Eukarya

Transparent antifouling coatings via nanoencapsulation of a biocide

A Floral Fragrance, Methyl Benzoate, is An Efficient Green Pesticide

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