An amphiphilic polypeptide, poly(sarcosine)- b-(l-Leu-Aib) (SL16), was reported to self-assemble into vesicles. A GxxxG motif, which is known to induce helix dimerization, is incorporated into the hydrophobic helical block of SL16 to synthesize poly(sarcosine)- b-(l-Leu-Aib)-(Gly-Aib-l-Leu-Aib-Gly-Aib)-(l-Leu-Aib) (SG16). SG16 shows helix association in ethanol at a high concentration and low temperatures, which is not observed with SL16. SG16 self-assembles into vesicles, but are found to be more susceptible to rupture by the addition of Triton X-100 than SL16 vesicles. A mixture of SL16 and SG16 self-assembles into small sheets and micelles likely because of mismatch of the modes of helix association arising from sterical accommodation of iso-butyl groups at the helix-helix interface.
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http://dx.doi.org/10.1021/acs.langmuir.9b00620 | DOI Listing |
J Struct Biol
December 2024
Department of Bioscience and Bioengineering, Indian Institute of Technology Jodhpur, NH 62, Nagaur Road, Karwar 342030, Rajasthan, India. Electronic address:
J Am Chem Soc
September 2024
Department of Chemistry, Massachusetts Institute of Technology, 170 Albany Street, Cambridge, Massachusetts 02139, United States.
The envelope (E) protein of SARS-CoV-2 is the smallest of the three structural membrane proteins of the virus. E mediates budding of the progeny virus in the endoplasmic reticulum Golgi intermediate compartment of the cell. It also conducts ions, and this channel activity is associated with the pathogenicity of SARS-CoV-2.
View Article and Find Full Text PDFProtein Sci
May 2024
Physical Biochemistry, University of Potsdam, Potsdam, Germany.
Intrinsically disordered late embryogenesis abundant (LEA) proteins play a central role in the tolerance of plants and other organisms to dehydration brought upon, for example, by freezing temperatures, high salt concentration, drought or desiccation, and many LEA proteins have been found to stabilize dehydration-sensitive cellular structures. Their conformational ensembles are highly sensitive to the environment, allowing them to undergo conformational changes and adopt ordered secondary and quaternary structures and to participate in formation of membraneless organelles. In an interdisciplinary approach, we discovered how the functional diversity of the Arabidopsis thaliana LEA protein COR15A found in vitro is encoded in its structural repertoire, with the stabilization of membranes being achieved at the level of secondary structure and the stabilization of enzymes accomplished by the formation of oligomeric complexes.
View Article and Find Full Text PDFBiochem Biophys Res Commun
May 2024
Department of Pharmacy, College of Pharmacy and Institute of Pharmaceutical Sciences, CHA University, Pocheon-si, 11160, Gyeonggi-Do, Republic of Korea. Electronic address:
Type II toxin-antitoxin (TA) systems are ubiquitously distributed genetic elements in prokaryotes and are crucial for cell maintenance and survival under environmental stresses. The antitoxin is a modular protein consisting of the disordered C-terminal region that physically contacts and neutralizes the cognate toxin and the well-folded N-terminal DNA binding domain responsible for autorepression of TA transcription. However, how the two functional domains communicate is largely unknown.
View Article and Find Full Text PDFProteins
January 2025
Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, Uttar Pradesh, India.
The recently discovered SWEET (Sugar Will Eventually be Exported Transporter) proteins are involved in the selective transport of monosaccharides and disaccharides. The prokaryotic counterparts, semiSWEETs, form dimers with each monomer forming a triple-helix transmembrane bundle (THB). The longer eukaryotic SWEETs have seven transmembrane helices with two THBs and a linker helix.
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