Previously, we demonstrated that the ∼130-kDa CyaA-hemolysin (CyaA-Hly, Met-Arg) from Bordetella pertussis was palmitoylated at Lys when co-expressed with CyaC-acyltransferase in Escherichia coli, and thus activated its hemolytic activity. Here, further investigation on a possible requirement of the N-terminal hydrophobic region (HP, Met-Leu) for toxin acylation was performed. The ∼100-kDa RTX (Repeat-in-ToXin) fragment (CyaA-RTX, Ala-Arg) containing the Lys-acylation region (AR, Ala-Gln), but lacking HP, was co-produced with CyaC in E. coli. Hemolysis assay indicated that CyaA-RTX showed no hemolytic activity. Additionally, MALDI-TOF/MS and LC-MS/MS analyses confirmed that CyaA-RTX was non-acylated, although the co-expressed CyaC-acyltransferase was able to hydrolyze its chromogenic substrate-p-nitrophenyl palmitate and acylate CyaA-Hly to become hemolytically active. Unlike CyaA-RTX, the ∼70-kDa His-tagged CyaA-HP/BI fragment which is hemolytically inactive and contains both HP and AR was constantly co-eluted with CyaC during IMAC-purification as the presence of CyaC was verified by Western blotting. Such potential interactions between the two proteins were also revealed by semi-native PAGE. Moreover, structural analysis via electrostatic potential calculations and molecular docking suggested that CyaA-HP comprising α1-α5 (Leu-Val) can interact with CyaC through several hydrogen and ionic bonds formed between their opposite electrostatic surfaces. Overall, our results demonstrated that the HP region of CyaA-Hly is conceivably required for not only membrane-pore formation but also functional association with CyaC-acyltransferase, and hence effective palmitoylation at Lys.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.bbrc.2018.04.007 | DOI Listing |
JACS Au
December 2024
Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
It has become increasingly evident that the conformational distributions of intrinsically disordered proteins or regions are strongly dependent on their amino acid compositions and sequence. To facilitate a systematic investigation of these sequence-ensemble relationships, we selected a set of 16 naturally occurring intrinsically disordered regions of identical length but with large differences in amino acid composition, hydrophobicity, and charge patterning. We probed their conformational ensembles with single-molecule Förster resonance energy transfer (FRET), complemented by circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopy as well as small-angle X-ray scattering (SAXS).
View Article and Find Full Text PDFPeerJ
December 2024
Department of Microbiology and Parasitology, Faculty of Medical Science, Naresuan University, Muang, Phitsanulok, Thailand.
Background: poses a significant public health threat. Phage-encoded antimicrobial peptides (AMPs) have emerged as promising candidates in the battle against antibiotic-resistant .
Methods: Antimicrobial peptides from the endolysin of bacteriophage were designed from bacteriophage vB_AbaM_PhT2 and vB_AbaAut_ChT04.
Int J Biol Macromol
December 2024
Jiangsu Optoelectronic Functional Materials Engineering Research Center, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189, China. Electronic address:
Passive radiative cooling (PRC) is an emerging sustainable technology that plays a key role for achieving the goal of carbon neutrality. However, several challenges remain for PRC materials in their practical application in building thermal management, including overcooling problems and unsatisfactory cooling efficiency caused by solar absorption and parasitic heat gains. In this work, fluorinated cellulose-based composite aerogels (FCCA) integrating thermal insulation and PRC were developed by a facile manufacturing strategy that combined phase separation and freeze-drying.
View Article and Find Full Text PDFBiochem Biophys Res Commun
December 2024
Department of Chemical Engineering, Osaka Metropolitan University, 1-1 Gakuen-cho, Naka-ku, Sakai, Osaka, 599-8531, Japan. Electronic address:
Acyl-acyl carrier protein (acyl-ACP) reductase (AAR) is a crucial enzyme in alka(e)ne production by recombinant Escherichia coli (E. coli). Engineered AAR expressed in E.
View Article and Find Full Text PDFCell Rep
December 2024
Center for Data Sciences, Brigham and Women's Hospital, Boston, MA, USA; Division of Genetics, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA; Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA; Program in Medical and Population Genetics, Broad Institute of MIT and Harvard, Cambridge, MA, USA; Division of Rheumatology, Inflammation, and Immunity, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA. Electronic address:
The amino acid sequence of the T cell receptor (TCR) varies between T cells of an individual's immune system. Particular TCR residues nearly guarantee mucosal-associated invariant T (MAIT) and natural killer T (NKT) cell transcriptional fates. To define how the TCR sequence affects T cell fates, we analyze the paired αβTCR sequence and transcriptome of 961,531 single cells.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!