Colorful packages : Encapsulation of fluorescent proteins in complex coacervate core micelles
Nolles, Antsje ; Westphal, Adrie H. ; Kleijn, J.M. ; Berkel, Willem J.H. van; Borst, Jan Willem - \ 2017
International Journal of Molecular Sciences 18 (2017)7. - ISSN 1661-6596
Anthozoa - Chromophore - Circular dichroism - Diblock copolymer - Dynamic light scattering - Fluorescence correlation spectroscopy - Hydrozoa - Polyelectrolyte - Protein structure - Steady-state fluorescence
Encapsulation of proteins can be beneficial for food and biomedical applications. To study their biophysical properties in complex coacervate core micelles (C3Ms), we previously encapsulated enhanced green fluorescent protein (EGFP) and its monomeric variant, mEGFP, with the cationic-neutral diblock copolymer poly(2-methyl-vinyl-pyridinium)n-b-poly(ethylene-oxide)m (P2MVPn-b-PEOm) as enveloping material. C3Ms with high packaging densities of fluorescent proteins (FPs) were obtained, resulting in a restricted orientational freedom of the protein molecules, influencing their structural and spectral properties. To address the generality of this behavior, we encapsulated seven FPs with P2MVP41-b-PEO205 and P2MVP128-b-PEO477. Dynamic light scattering and fluorescence correlation spectroscopy showed lower encapsulation efficiencies for members of the Anthozoa class (anFPs) than for Hydrozoa FPs derived from Aequorea victoria (avFPs). Far-UV CD spectra of the free FPs showed remarkable differences between avFPs and anFPs, caused by rounder barrel structures for avFPs and more elliptic ones for anFPs. These structural differences, along with the differences in charge distribution, might explain the variations in encapsulation efficiency between avFPs and anFPs. Furthermore, the avFPs remain monomeric in C3Ms with minor spectral and structural changes. In contrast, the encapsulation of anFPs gives rise to decreased quantum yields (monomeric Kusabira Orange 2 (mKO2) and Tag red fluorescent protein (TagRFP)) or to a pKa shift of the chromophore (FP variant mCherry).
First Record of Porpita porpita (Cnidaria: Hydrozoa) from the coral reef ecosystem, Bangladesh
Shah Nawaz Chowdhury, M. ; Sharifuzzaman, S.M. ; Chowdhury, Sayedur Rahman ; Rashed-Un-Nabi, Md ; Hossain, M.S. - \ 2016
Ocean Science Journal 51 (2016)2. - ISSN 1738-5261 - p. 293 - 297.
Bangladesh - Bay of Bengal - Hydrozoa - Porpita - Saint Martin’s Island
The occurrence of Porpita porpita is reported, for the first time, in the coral island of St. Martin’s located in the southeastern coastal region of Bangladesh. P. porpita was found to occur in the lower littoral zone and beach rock pools, together with molluscan species, and collected during the pre-monsoon season when both water temperature (> 30°C) and salinity (> 30‰) tend to reach a maximum. This study recounts some details on the discovery and description of the species, and thus extends the global distribution and range limits of the genus Porpita.