Limits...
Epigallocatechin-3-gallate rapidly remodels PAP85-120, SEM1(45-107), and SEM2(49-107) seminal amyloid fibrils.

Castellano LM, Hammond RM, Holmes VM, Weissman D, Shorter J - Biol Open (2015)

Bottom Line: Here, we confirm that the green tea polyphenol, epigallocatechin-3-gallate (EGCG), slowly remodels fibrils formed by PAP248-286 termed SEVI (semen derived enhancer of viral infection) and also exerts a direct anti-viral effect.We elucidate for the first time that EGCG remodels PAP85-120, SEM1(45-107), and SEM2(49-107) fibrils more rapidly than SEVI fibrils.The combined anti-amyloid and anti-viral properties of EGCG could have utility in preventing HIV transmission.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.

No MeSH data available.


Related in: MedlinePlus

EGCG rapidly remodels PAP85-120 amyloid fibrils. (A-D) PAP85-120 fibrils (20 µM) were incubated with buffer or EGCG (200 µM) for 0−24 h. Fibril integrity was assessed by measuring: ThT fluorescence intensity (A), OC immunoreactivity (B), turbidity (C), or sedimentation analysis (D). Values represent means±s.e.m. (n=3). (E) Transmission electron micrographs of PAP85-120 fibrils incubated with buffer (untreated) or EGCG for 6 h. Scale bar: 500 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4582112&req=5

BIO010215F2: EGCG rapidly remodels PAP85-120 amyloid fibrils. (A-D) PAP85-120 fibrils (20 µM) were incubated with buffer or EGCG (200 µM) for 0−24 h. Fibril integrity was assessed by measuring: ThT fluorescence intensity (A), OC immunoreactivity (B), turbidity (C), or sedimentation analysis (D). Values represent means±s.e.m. (n=3). (E) Transmission electron micrographs of PAP85-120 fibrils incubated with buffer (untreated) or EGCG for 6 h. Scale bar: 500 nm.

Mentions: Using a ten-fold excess of EGCG, we found that the ThT fluorescence intensity of PAP85-120 fibrils decreased to ∼55% of the initial value immediately after the addition of EGCG and decreased by ∼95% after 6 h (Fig. 2A). Several studies have shown that EGCG does not interfere with ThT fluorescence by some non-specific mechanism (Bieschke et al., 2010; Cao and Raleigh, 2012; Meng et al., 2010; Roberts et al., 2009). Thus, we attribute this rapid decay of ThT fluorescence to rapid fibril remodeling, which has also been observed with EGCG and amylin fibrils (Cao and Raleigh, 2012; Meng et al., 2010). However, using three other measures of fibril integrity we did not observe any alteration immediately after addition of EGCG, but remodeling was apparent after 2 h (Fig. 2B-D). Thus, ThT fluorescence might detect a very early event in PAP85-120 fibril remodeling by EGCG, such as remodeling of ThT-binding sites, or EGCG might interfere with ThT binding-associated fluorescence (Palhano et al., 2013). Nonetheless, all measures of fibril integrity indicated that the remodeling of PAP85-120 by EGCG occurred significantly more rapidly than EGCG-driven remodeling of SEVI fibrils (Fig. 2), which were largely intact after 6 h (Fig. 1A,D-F). Analysis of PAP85-120 fibrils treated with EGCG for 6 h by TEM showed predominately small oligomeric species, as well as a few short fibrils (Fig. 2E). Thus, EGCG rapidly remodels PAP85-120 fibrils.Fig. 2.


Epigallocatechin-3-gallate rapidly remodels PAP85-120, SEM1(45-107), and SEM2(49-107) seminal amyloid fibrils.

Castellano LM, Hammond RM, Holmes VM, Weissman D, Shorter J - Biol Open (2015)

EGCG rapidly remodels PAP85-120 amyloid fibrils. (A-D) PAP85-120 fibrils (20 µM) were incubated with buffer or EGCG (200 µM) for 0−24 h. Fibril integrity was assessed by measuring: ThT fluorescence intensity (A), OC immunoreactivity (B), turbidity (C), or sedimentation analysis (D). Values represent means±s.e.m. (n=3). (E) Transmission electron micrographs of PAP85-120 fibrils incubated with buffer (untreated) or EGCG for 6 h. Scale bar: 500 nm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4582112&req=5

BIO010215F2: EGCG rapidly remodels PAP85-120 amyloid fibrils. (A-D) PAP85-120 fibrils (20 µM) were incubated with buffer or EGCG (200 µM) for 0−24 h. Fibril integrity was assessed by measuring: ThT fluorescence intensity (A), OC immunoreactivity (B), turbidity (C), or sedimentation analysis (D). Values represent means±s.e.m. (n=3). (E) Transmission electron micrographs of PAP85-120 fibrils incubated with buffer (untreated) or EGCG for 6 h. Scale bar: 500 nm.
Mentions: Using a ten-fold excess of EGCG, we found that the ThT fluorescence intensity of PAP85-120 fibrils decreased to ∼55% of the initial value immediately after the addition of EGCG and decreased by ∼95% after 6 h (Fig. 2A). Several studies have shown that EGCG does not interfere with ThT fluorescence by some non-specific mechanism (Bieschke et al., 2010; Cao and Raleigh, 2012; Meng et al., 2010; Roberts et al., 2009). Thus, we attribute this rapid decay of ThT fluorescence to rapid fibril remodeling, which has also been observed with EGCG and amylin fibrils (Cao and Raleigh, 2012; Meng et al., 2010). However, using three other measures of fibril integrity we did not observe any alteration immediately after addition of EGCG, but remodeling was apparent after 2 h (Fig. 2B-D). Thus, ThT fluorescence might detect a very early event in PAP85-120 fibril remodeling by EGCG, such as remodeling of ThT-binding sites, or EGCG might interfere with ThT binding-associated fluorescence (Palhano et al., 2013). Nonetheless, all measures of fibril integrity indicated that the remodeling of PAP85-120 by EGCG occurred significantly more rapidly than EGCG-driven remodeling of SEVI fibrils (Fig. 2), which were largely intact after 6 h (Fig. 1A,D-F). Analysis of PAP85-120 fibrils treated with EGCG for 6 h by TEM showed predominately small oligomeric species, as well as a few short fibrils (Fig. 2E). Thus, EGCG rapidly remodels PAP85-120 fibrils.Fig. 2.

Bottom Line: Here, we confirm that the green tea polyphenol, epigallocatechin-3-gallate (EGCG), slowly remodels fibrils formed by PAP248-286 termed SEVI (semen derived enhancer of viral infection) and also exerts a direct anti-viral effect.We elucidate for the first time that EGCG remodels PAP85-120, SEM1(45-107), and SEM2(49-107) fibrils more rapidly than SEVI fibrils.The combined anti-amyloid and anti-viral properties of EGCG could have utility in preventing HIV transmission.

View Article: PubMed Central - PubMed

Affiliation: Department of Biochemistry and Biophysics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA Pharmacology Graduate Group, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA 19104, USA.

No MeSH data available.


Related in: MedlinePlus