John Karas

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..

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..

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..

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..

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..

Synthesis and structure-activity relationships of teixobactin

John A Karas, Fan Chen, Elena K Schneider-Futschik, Zhisen Kang, Maytham Hussein, James Swarbrick, Daniel Hoyer, Andrew M Giltrap, Richard J Payne, Jian Li, Tony Velkov

Journal article  |  2019  |  ANNALS OF THE NEW YORK ACADEMY OF SCIENCES

The discovery of antibiotics has led to the effective treatment of bacterial infections that were otherwise fatal and has had a tr..