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Eun Ji Park, Dong Hee Na
The separation mechanism of PEGylated peptides in reversed-phase high-performance liquid chromatography (RP-HPLC) is complex, because the PEGylated molecules exhibit physicochemical properties that are different from those of the parent molecules and have heterogeneous structure. Since most separation studies have focused on the hydrophobicity of the peptide relative to poly(ethylene glycol) (PEG), the role of PEG in the separation of PEGylated peptides on RP-HPLC is not clear. To elucidate the effect of the attached PEG on the retention of PEGylated peptides on RP-HPLC, the mono-PEGylated forms of collagen pentapeptide and octreotide were fractionated drop-by-drop from the outlet of the HPLC system and each drop was subjected to matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS)...
October 25, 2016: Analytical Chemistry
Shu Jiang, Yulan Liu, Jing Wang, Yue Zhang, Yaocheng Rui, Yuefan Zhang, Tiejun Li
Monocyte locomotion inhibitory factor (MLIF), a heat-stable pentapeptide produced by Entamoeba histolytica, has anti-inflammatory function and protective effect on ischemic stroke. In this study, we evaluated the effect of MLIF on myocardial ischemia. The myocardial ischemia reperfusion (I/R) model was established by ligation of the left anterior descending branch (LAD) using 8-0 silk suture for 30min followed by 3h reperfusion in mice. After sacrifice, the serum concentrations of cardiac troponin I (cTnI), creatine kinase (CK), lactate dehydrogenase (LDH) as well as the heart infarct size were measured...
October 20, 2016: Life Sciences
Monika Łęgowska, Yveline Hamon, Anna Wojtysiak, Renata Grzywa, Marcin Sieńczyk, Timo Burster, Brice Korkmaz, Adam Lesner
Cathepsin C is a wildly expressed cysteine exopeptidase that is mostly recognized for the activation of the granule-associated proinflammatory serine proteases in neutrophils, cytotoxic T lymphocytes and mast cells. It has been shown that the enzyme can be secreted extracellularly; however, its occurrence in human bodily fluids/physiological samples has not been thoroughly studied. In the course of this study, the first fluorescence resonance energy transfer peptides for the measurement of the activity of human cathepsin C were designed and synthesized...
October 13, 2016: Archives of Biochemistry and Biophysics
Kandasamy Eniyan, Anuradha Kumar, Geetha Vani Rayasam, Andrej Perdih, Urmi Bajpai
The cell wall of Mycobacterium tuberculosis (Mtb) consists of peptidoglycan, arabinogalactan and mycolic acids. The cytoplasmic steps in the peptidoglycan biosynthetic pathway, catalyzed by the Mur (A-F) enzymes, involve the synthesis of UDP-n-acetylmuramyl pentapeptide, a key precursor molecule required for the formation of the peptidoglycan monomeric building blocks. Mur enzymes are indispensable for cell integrity and their lack of counterparts in eukaryotes suggests them to be promising Mtb drug targets...
October 13, 2016: Scientific Reports
Cristian Gustavo Aguilera Rossi, Paulino Gómez-Puertas, Juan Alfonso Ayala Serrano
BACKGROUND: Community and nosocomial infections by Pseudomonas aeruginosa still create a major therapeutic challenge. The resistance of this opportunist pathogen to β-lactam antibiotics is determined mainly by production of the inactivating enzyme AmpC, a class C cephalosporinase with a regulation system more complex than those found in members of the Enterobacteriaceae family. This regulatory system also participates directly in peptidoglycan turnover and recycling. One of the regulatory mechanisms for AmpC expression, recently identified in clinical isolates, is the inactivation of LMM-PBP4 (Low-Molecular-Mass Penicillin-Binding Protein 4), a protein whose catalytic activity on natural substrates has remained uncharacterized until now...
October 6, 2016: BMC Microbiology
Beilei Lei, Michael L James, Ji Liu, Guanen Zhou, Talaignair N Venkatraman, Christopher D Lascola, Shawn K Acheson, Laura G Dubois, Daniel T Laskowitz, Haichen Wang
Presently, no pharmacological treatments have been demonstrated to improve long-term functional outcomes following intracerebral hemorrhage (ICH). Clinical evidence associates apolipoprotein E (apoE) genotype with ICH incidence and outcome. While apoE modifies neuroinflammatory responses through its adaptive role in glial downregulation, intact apoE holoprotein is too large to cross the blood-brain barrier (BBB). Therefore, we developed a 5-amino acid peptide - CN-105 - that mimics the polar face of the apoE helical domain involved in receptor interactions...
October 7, 2016: Scientific Reports
Doo Ri An, Ha Na Im, Jun Young Jang, Hyoun Sook Kim, Jieun Kim, Hye Jin Yoon, Dusan Hesek, Mijoon Lee, Shahriar Mobashery, Soon-Jong Kim, Se Won Suh
Colonization of the human gastric mucosa by Helicobacter pylori requires its high motility, which depends on the helical cell shape. In H. pylori, several genes (csd1, csd2, csd3/hdpA, ccmA, csd4, csd5, and csd6) play key roles in determining the cell shape by alteration of cross-linking or by trimming of peptidoglycan stem peptides. H. pylori Csd1, Csd2, and Csd3/HdpA are M23B metallopeptidase family members and may act as d,d-endopeptidases to cleave the d-Ala4-mDAP3 peptide bond of cross-linked dimer muropeptides...
2016: PloS One
Yukio Koizumi, Kenichiro Nagai, Keiji Hasumi, Keiji Kuba, Toshihiro Sugiyama
The formation of blood clots in blood vessels causes severe ischemic diseases such as cerebral infarction and myocardial infarction. While searching for microbial products that increase fibrinolytic activity using an in vitro fibrin degradation assay, we found malformin A1, a disulfide form of cyclo(-d-Cys-d-Cys-l-Val-d-Leu-l-Ile-), as an active compound. In this study, we synthesized malformin derivatives using a solid-phase peptide synthesis method and evaluated their fibrinolytic activity and cytotoxicity...
September 16, 2016: Bioorganic & Medicinal Chemistry Letters
Julia Deibert, Daniel Kühner, Mark Stahl, Elif Koeksoy, Ute Bertsche
The Gram-positive bacterium Staphylococcus carnosus (S. carnosus) TM300 is an apathogenic staphylococcal species commonly used in meat starter cultures. As with all Gram-positive bacteria, its cytoplasmic membrane is surrounded by a thick peptidoglycan (PGN) or murein sacculus consisting of several layers of glycan strands cross-linked by peptides. In contrast to pathogenic staphylococci, mainly Staphylococcus aureus (S. aureus), the chemical composition of S. carnosus PGN is not well studied so far. UPLC/MS analysis of enzymatically digested S...
2016: Antibiotics
Matthieu Fonvielle, Nicolas Sakkas, Laura Iannazzo, Chloé Le Fournis, Delphine Patin, Dominique Mengin-Lecreulx, Afaf El-Sagheer, Emmanuelle Braud, Sébastien Cardon, Tom Brown, Michel Arthur, Mélanie Etheve-Quelquejeu
RNA functionalization is challenging due to the instability of RNA and the limited range of available enzymatic reactions. We developed a strategy based on solid phase synthesis and post-functionalization to introduce an electrophilic site at the 3' end of tRNA analogues. The squarate diester used as an electrophile enabled sequential amidation and provided asymmetric squaramides with high selectivity. The squaramate-RNAs specifically reacted with the lysine of UDP-MurNAc-pentapeptide, a peptidoglycan precursor used by the aminoacyl-transferase FemXWv for synthesis of the bacterial cell wall...
October 17, 2016: Angewandte Chemie
A M Salem, S J Jones, I R Ellis, R G Chadwick
AIMS: Placement of a restoration to treat root caries disrupts many tissues. There is scope for the restorative material to interact with these to augment reductions in micro leakage afforded by an adhesive restorative material. OBJECTIVES: 1) To investigate the effects of incorporating bioactive molecules into a glass polyalkenoate (GPA) 2) To quantify the changes in physical properties of the material. METHODS: Biocompatibility of the GPA cement (Chemfil Superior, Dentsply De Trey, Konstanz, Germany) in unmodified and modified forms was ascertained using cell culture techniques...
November 2016: Journal of Dentistry
Lamei Yu, Kuichang Yuan, Hoang Thi Ai Phuong, Byung Mun Park, Suhn Hee Kim
Angiotensin-(1-5) [Ang-(1-5)], which is a metabolite of Angiotensin-(1-7) [Ang-(1-7)] catalyzed by angiotensin-converting enzyme (ACE), is a pentapeptide of the renin-angiotensin system (RAS). It has been reported that Ang-(1-7) and Ang-(1-9) stimulate the secretion of atrial natriuretic peptide (ANP) via Mas receptor (Mas R) and Ang II type 2 receptor (AT2R), respectively. However, it still remains unknown whether Ang-(1-5) has a similar function to Ang-(1-7). We investigated the effect of Ang-(1-5) on ANP secretion and to define its signaling pathway using isolated perfused beating rat atria...
September 20, 2016: Peptides
Henrik Harms, Kenji L Kurita, Li Pan, Paul G Wahome, Haiyin He, A Douglas Kinghorn, Guy T Carter, Roger G Linington
Cyanobacteria possess a unique capacity for the production of structurally novel secondary metabolites compared to the biosynthetic abilities of other environmental prokaryotes such as bacteria of the genus Streptomyces. Two different strategies to explore cyanobacteria-derived natural products have been explored previously: (1) cultivation of single cyanobacterial strains, in bioreactors for example; (2) bulk collections from the environment of so called 'algal blooms' that are dominated by cyanobacteria. In this study a new environmentally friendly collection technique for obtaining large quantities of algal bloom biomass was utilized...
October 15, 2016: Bioorganic & Medicinal Chemistry Letters
Jiajia Liu, Yajun Huang, Weiping Zheng
In the current study, we discovered that a side chain-to-side chain cyclic pentapeptide harboring a central N(ε)-carboxyethyl-thiocarbamoyl-lysine residue behaved as a strong and selective (versus human SIRT1/2/3/6) inhibitor against human SIRT5-catalyzed deacylation reaction. This compound was also found to be proteolytically much more stable than its linear counterpart. This compound could be a valuable lead for developing stronger, selective, metabolically stable, and cell permeable human SIRT5 inhibitors...
2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Hiroki Otaki, Kiyoshi Yagi, Shun-Ichi Ishiuchi, Masaaki Fujii, Yuji Sugita
An accurate theoretical prediction of the vibrational spectrum of polypeptides remains to be a challenge due to (1) their conformational flexibility and (2) non-negligible anharmonic effects. The former makes the search for conformers that contribute to the spectrum difficult, and the latter requires an expensive, quantum mechanical calculation for both electrons and vibrations. Here, we propose a new theoretical approach, which implements an enhanced conformational sampling by the replica-exchange molecular dynamics method, a structural clustering to identify distinct conformations, and a vibrational structure calculation by the second-order vibrational quasi-degenerate perturbation theory (VQDPT2)...
October 6, 2016: Journal of Physical Chemistry. B
Liangliang Yu, Yan Liu, Yumin Liu, Qiong Li, Guirong Tang, Li Luo
Over-production of functional PSK-α in Arabidopsis caused increases in both plant cell growth and biomass and induced male sterility by regulating cell wall development. Phytosulfokine-α (PSK-α) is a novel disulfated pentapeptide hormone that is involved in promoting plant cell growth. Although a role for PSK-α in stimulating protoplast expansion has been suggested, how PSK-α regulates cell growth in planta remains poorly understood. In this study, we found that overexpression of the normal PSK-α precursor gene AtPSK4, which resulted in high levels of PSK-α, caused longer roots and larger leaves with enlarged cells...
September 12, 2016: Plant Cell Reports
Sonya VanPatten, Shan Sun, Mingzhu He, Kai Fan Cheng, Ahmad Altiti, Angelos Papatheodorou, Czeslawa Kowal, Venkatesh Jeganathan, James M Crawford, Ona Bloom, Bruce T Volpe, Christian Grant, Nathalie Meurice, Thomas R Coleman, Betty Diamond, Yousef Al-Abed
Systemic lupus erythematosus is an autoimmune disease that can affect numerous tissues and is characterized by the production of nuclear antigen-directed autoantibodies (e.g., anti-dsDNA). Using a combination of virtual and ELISA-based screens, we made the intriguing discovery that several HIV-protease inhibitors can function as decoy antigens to specifically inhibit the binding of anti-dsDNA antibodies to target antigens such as dsDNA and pentapeptide DWEYS. Computational modeling revealed that HIV-protease inhibitors comprised structural features present in DWEYS and predicted that analogues containing more flexible backbones would possess preferred binding characteristics...
October 13, 2016: Journal of Medicinal Chemistry
Jignesh Lunagariya, Shenghui Zhong, Jianwei Chen, Defa Bai, Poonam Bhadja, Weili Long, Xiaojian Liao, Xiaoli Tang, Shihai Xu
Herein, we report design and synthesis of novel 26 galaxamide analogues with N-methylated cyclo-pentapeptide, and their in vitro anti-tumor activity towards the panel of human tumor cell line, such as, A549, A549/DPP, HepG2 and SMMC-7721 using MTT assay. We have also investigated the effect of galaxamide and its representative analogues on growth, cell-cycle phases, and induction of apoptosis in SMMC-7721 cells in vitro. Reckon with the significance of conformational space and N-Me aminoacid (aa) comprising this compound template, we designed the analogues with modification in N-Me-aa position, change in aa configuration from l to d aa and substitute one Leu-aa to d/l Phe-aa residue with respective to the parent structure...
September 3, 2016: Marine Drugs
Darja Kanduc
Two main factors can affect the development of ebolavirus immunotherapeutics: the vast peptide commonality between ebolavirus and human proteins, and the high rate of spontaneous mutation of ebolavirus within its human host. Indeed, the viral versus human peptide overlap may represent a relevant source of autoimmune crossreactions following vaccination, while ebolavirus genome mutations can limit and/or nullify a vaccine response. Aiming at defining safe and effective peptide-based vaccines to fight ebola disease, this study analyzed a recently described Ebola virus isolate (Hoenen et al...
September 2, 2016: Current Drug Discovery Technologies
James T MacDonald, Burak V Kabasakal, David Godding, Sebastian Kraatz, Louie Henderson, James Barber, Paul S Freemont, James W Murray
The ability to design and construct structures with atomic level precision is one of the key goals of nanotechnology. Proteins offer an attractive target for atomic design because they can be synthesized chemically or biologically and can self-assemble. However, the generalized protein folding and design problem is unsolved. One approach to simplifying the problem is to use a repetitive protein as a scaffold. Repeat proteins are intrinsically modular, and their folding and structures are better understood than large globular domains...
September 13, 2016: Proceedings of the National Academy of Sciences of the United States of America
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