John Karas

The effect of substance P and its common in vivo-formed metabolites on MRGPRX2 and human mast cell activation

Lin Hsin, Nithya A Fernandopulle, Jie Ding, Chris Lumb, Nicholas Veldhuis, John A Karas, Susan E Northfield, Graham A Mackay

Journal article  |  2022  |  PHARMACOLOGY RESEARCH & PERSPECTIVES

The tachykinin neuropeptide substance P (SP) is the canonical agonist peptide for the neurokinin 1 receptor (NK1 R). More recently..

Endosomal escape cell-penetrating peptides significantly enhance pharmacological effectiveness and CNS activity of systemically administered antisense oligonucleotides

Mohadeseh Dastpeyman, Ramin Sharifi, Azin Amin, John A Karas, Brittany Cuic, Yijun Pan, Joseph A Nicolazzo, Bradley J Turner, Fazel Shabanpoor

Journal article  |  2021  |  INTERNATIONAL JOURNAL OF PHARMACEUTICS

Antisense oligonucleotides (ASOs) are an emerging class of gene-specific therapeutics for diseases associated with the central ner..

The Chemical Synthesis of Insulin: An Enduring Challenge

John A Karas, John D Wade, Mohammed Akhter Hossain

Journal article  |  2021  |  CHEMICAL REVIEWS

The pancreatic peptide hormone insulin, first discovered exactly 100 years ago, is essential for glycemic control and is used as a..

Modular Synthesis of Trifunctional Peptide-oligonucleotide Conjugates via Native Chemical Ligation

Mohadeseh Dastpeyman, John A Karas, Azin Amin, Bradley J Turner, Fazel Shabanpoor

Journal article  |  2021  |  FRONTIERS IN CHEMISTRY

Cell penetrating peptides (CPPs) are being increasingly used as efficient vectors for intracellular delivery of biologically activ..

Structure-Activity Relationships of Daptomycin Lipopeptides

John A Karas, Glen P Carter, Benjamin P Howden, Adrianna M Turner, Olivia KA Paulin, James D Swarbrick, Mark A Baker, Jian Li, Tony Velkov

Journal article  |  2020  |  JOURNAL OF MEDICINAL CHEMISTRY

Daptomycin is a calcium-dependent cyclic lipodepsipeptide derived from the soil saprotroph Streptomyces roseosporus, and its antib..

The Antimicrobial Activity of Cannabinoids

John A Karas, Labell JM Wong, Olivia KA Paulin, Amna C Mazeh, Maytham H Hussein, Jian Li, Tony Velkov

Journal article  |  2020  |  Antibiotics

A post-antibiotic world is fast becoming a reality, given the rapid emergence of pathogens that are resistant to current drugs. Th..

The Killing Mechanism of Teixobactin against Methicillin-Resistant Staphylococcus aureus: an Untargeted Metabolomics Study

Maytham Hussein, John A Karas, Elena K Schneider-Futschik, Fan Chen, James Swarbrick, Olivia KA Paulin, Daniel Hoyer, Mark Baker, Yan Zhu, Jian Li, Tony Velkov

Journal article  |  2020  |  mSystems

Antibiotics have served humankind through their use in modern medicine as effective treatments for otherwise fatal bacterial infec..

Structure of micelle bound cationic peptides by NMR spectroscopy using a lanthanide shift reagent

James D Swarbrick, John A Karas, Jian Li, Tony Velkov

Journal article  |  2020  |  Chemical Communications

[Tm(DPA)3]3- was used to generate multiple, paramagnetic nuclear Overhauser effect NMR spectra of cationic peptides when weakly bo..

1,3-Dichloroacetone: A Robust Reagent for Preparing Bicyclic Peptides

Qingqing Lin, Denham Hopper, Haoyue Zhang, Jordan Sfyris Qoon, Zihan Shen, John A Karas, Richard A Hughes, Susan E Northfield

Journal article  |  2020  |  ACS OMEGA

The chemical synthesis of cyclic peptides is a well-established area of research. This has been further expanded by development of..

Total Chemical Synthesis of a Nonfibrillating Human Glycoinsulin

Mohammed Akhter Hossain, Rio Okamoto, John A Karas, Praveen Praveen, Mengjie Liu, Briony E Forbes, John D Wade, Yasuhiro Kajihara

Journal article  |  2020  |  JOURNAL OF THE AMERICAN CHEMICAL SOCIETY

Glycosylation is an accepted strategy to improve the therapeutic value of peptide and protein drugs. Insulin and its analogues are..