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Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

Rittschof D, Orihuela B, Harder T, Stafslien S, Chisholm B, Dickinson GH - PLoS ONE (2011)

Bottom Line: Mixtures of compounds were found on 2 commercial and 8 model silicone coatings.Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents.Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties.

View Article: PubMed Central - PubMed

Affiliation: MSC Division, Duke University Marine Laboratory, Nicholas School of the Environment, Beaufort, North Carolina, United States of America. ritt@duke.edu

ABSTRACT

Background: Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity.

Methodology/principal findings: GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents.

Conclusions/significance: Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

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Related in: MedlinePlus

Effect of silicone eluates on purified trypsin and transglutaminase activity (from porcine and guinea pig respectively).Elution was conducted by swabbing model polysiloxane coatings with a dry cotton swab. Compounds taken up onto the cotton swab were eluted with methanol, methanol was then dried completely, and residual was resuspended directly in assay buffer with no additional methanol added. Controls were clean cotton swabs that had not been in contact with polysiloxane, which were eluted, dried, and resuspended in assay buffer. Model polysiloxane coatings were composed of low or high molecular weight (MW) oligomers, and were prepared with high or low concentration of cross-linker (XL), with or without silicone oil. Data are expressed as percent change in OD405 (trypsin) or OD450 (transglutaminase) from control. Means and SEM are shown. n = 2 replicates.
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pone-0016487-g006: Effect of silicone eluates on purified trypsin and transglutaminase activity (from porcine and guinea pig respectively).Elution was conducted by swabbing model polysiloxane coatings with a dry cotton swab. Compounds taken up onto the cotton swab were eluted with methanol, methanol was then dried completely, and residual was resuspended directly in assay buffer with no additional methanol added. Controls were clean cotton swabs that had not been in contact with polysiloxane, which were eluted, dried, and resuspended in assay buffer. Model polysiloxane coatings were composed of low or high molecular weight (MW) oligomers, and were prepared with high or low concentration of cross-linker (XL), with or without silicone oil. Data are expressed as percent change in OD405 (trypsin) or OD450 (transglutaminase) from control. Means and SEM are shown. n = 2 replicates.

Mentions: Eight model polysiloxanes were rubbed with methanol cleaned, dry cotton swabs. Sorped compounds were eluted from swabs with methanol, dried and resuspended in enzyme assay buffer. Controls were methanol cleaned and dried cotton swabs eluted with methanol, dried, and then resuspended in assay buffer. All model polysiloxane coating residues inhibited trypsin activity as compared to controls (Figure 6). In each case, the percent change from control was greater in coatings with silicone oil. Transglutaminase activity was inhibited as compared to controls for each of the silicones that did not contain silicone oil (Figure 6). Three of four model silicones with silicone oil showed a 34 to 57% promotion of transglutaminase activity as compared to controls. Variation between replicates was less than 27% for all enzyme assays.


Compounds from silicones alter enzyme activity in curing barnacle glue and model enzymes.

Rittschof D, Orihuela B, Harder T, Stafslien S, Chisholm B, Dickinson GH - PLoS ONE (2011)

Effect of silicone eluates on purified trypsin and transglutaminase activity (from porcine and guinea pig respectively).Elution was conducted by swabbing model polysiloxane coatings with a dry cotton swab. Compounds taken up onto the cotton swab were eluted with methanol, methanol was then dried completely, and residual was resuspended directly in assay buffer with no additional methanol added. Controls were clean cotton swabs that had not been in contact with polysiloxane, which were eluted, dried, and resuspended in assay buffer. Model polysiloxane coatings were composed of low or high molecular weight (MW) oligomers, and were prepared with high or low concentration of cross-linker (XL), with or without silicone oil. Data are expressed as percent change in OD405 (trypsin) or OD450 (transglutaminase) from control. Means and SEM are shown. n = 2 replicates.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3040736&req=5

pone-0016487-g006: Effect of silicone eluates on purified trypsin and transglutaminase activity (from porcine and guinea pig respectively).Elution was conducted by swabbing model polysiloxane coatings with a dry cotton swab. Compounds taken up onto the cotton swab were eluted with methanol, methanol was then dried completely, and residual was resuspended directly in assay buffer with no additional methanol added. Controls were clean cotton swabs that had not been in contact with polysiloxane, which were eluted, dried, and resuspended in assay buffer. Model polysiloxane coatings were composed of low or high molecular weight (MW) oligomers, and were prepared with high or low concentration of cross-linker (XL), with or without silicone oil. Data are expressed as percent change in OD405 (trypsin) or OD450 (transglutaminase) from control. Means and SEM are shown. n = 2 replicates.
Mentions: Eight model polysiloxanes were rubbed with methanol cleaned, dry cotton swabs. Sorped compounds were eluted from swabs with methanol, dried and resuspended in enzyme assay buffer. Controls were methanol cleaned and dried cotton swabs eluted with methanol, dried, and then resuspended in assay buffer. All model polysiloxane coating residues inhibited trypsin activity as compared to controls (Figure 6). In each case, the percent change from control was greater in coatings with silicone oil. Transglutaminase activity was inhibited as compared to controls for each of the silicones that did not contain silicone oil (Figure 6). Three of four model silicones with silicone oil showed a 34 to 57% promotion of transglutaminase activity as compared to controls. Variation between replicates was less than 27% for all enzyme assays.

Bottom Line: Mixtures of compounds were found on 2 commercial and 8 model silicone coatings.Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents.Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties.

View Article: PubMed Central - PubMed

Affiliation: MSC Division, Duke University Marine Laboratory, Nicholas School of the Environment, Beaufort, North Carolina, United States of America. ritt@duke.edu

ABSTRACT

Background: Attachment strength of fouling organisms on silicone coatings is low. We hypothesized that low attachment strength on silicones is, in part, due to the interaction of surface available components with natural glues. Components could alter curing of glues through bulk changes or specifically through altered enzyme activity.

Methodology/principal findings: GC-MS analysis of silicone coatings showed surface-available siloxanes when the coatings were gently rubbed with a cotton swab for 15 seconds or given a 30 second rinse with methanol. Mixtures of compounds were found on 2 commercial and 8 model silicone coatings. The hypothesis that silicone components alter glue curing enzymes was tested with curing barnacle glue and with commercial enzymes. In our model, barnacle glue curing involves trypsin-like serine protease(s), which activate enzymes and structural proteins, and a transglutaminase which cross-links glue proteins. Transglutaminase activity was significantly altered upon exposure of curing glue from individual barnacles to silicone eluates. Activity of purified trypsin and, to a greater extent, transglutaminase was significantly altered by relevant concentrations of silicone polymer constituents.

Conclusions/significance: Surface-associated silicone compounds can disrupt glue curing and alter enzyme properties. Altered curing of natural glues has potential in fouling management.

Show MeSH
Related in: MedlinePlus