John Karas

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 impact of backbone N-methylation on the structure-activity relationship of Leu(10)-teixobactin

Tony Velkov, James D Swarbrick, Maytham H Hussein, Elena K Schneider-Futschik, Daniel Hoyer, Jian Li, John A Karas

Journal article  |  2019  |  Journal of Peptide Science

Rapid Photolysis-Mediated Folding of Disulfide-Rich Peptides

Nitin A Patil, John A Karas, John D Wade, Mohammed Akhter Hossain, Julien Tailhades

Journal article  |  2019  |  Chemistry – A European Journal

Thiol-Cyanobenzothiazole Ligation for the Efficient Preparation of Peptide-PNA Conjugates

Nitin A Patil, John A Karas, Bradley J Turner, Fazel Shabanpoor

Journal article  |  2019  |  Bioconjugate Chemistry

Nuclear Magnetic Resonance Study of the Peptide FRANCESSEPAROVIC

JA Karas, DW Keizer, MA Sani

Journal article  |  2019  |  Australian Journal of Chemistry

As an eminent ambassador of STEM and renowned NMR spectroscopist, Frances Separovic is an internationally famous name, but could i..

Sputum Active Polymyxin Lipopeptides: Activity against Cystic Fibrosis Pseudomonas aeruginosa Isolates and Their Interactions with Sputum Biomolecules

Elena K Schneider-Futschik, Olivia KA Paulin, Daniel Hoyer, Kade D Roberts, James Ziogas, Mark A Baker, John Karas, Jian Li, Tony Velkov

Journal article  |  2018  |  ACS INFECTIOUS DISEASES

The Assembly of Fluorescently Labeled Peptide-Oligonucleotide Conjugates via Orthogonal Ligation Strategies

John Karas, Bradley J Turner, Fazel Shabanpoor

Book Chapter  |  2018  |  Methods in Molecular Biology

Rhenium and Technetium-oxo Complexes with Thioamide Derivatives of Pyridylhydrazine Bifunctional Chelators Conjugated to the Tumour Targeting Peptides Octreotate and Cyclic-RGDfK

Andrea J North, John A Karas, Michelle T Ma, Philip J Blower, Uwe Ackermann, Jonathan M White, Paul S Donnelly

Journal article  |  2017  |  Inorganic Chemistry

The efficient synthesis and purification of amyloid-beta(1-42) using an oligoethylene glycol-containing photocleavable lysine tag

John A Karas, Asif Noor, Christine Schieber, Timothy U Connell, Frances Separovic, Paul S Donnelly

Journal article  |  2017  |  Chemical Communications

Chemical Synthesis and Characterization of an Equinatoxin II(1-85) Analogue

John A Karas, Marc-Antoine Sani, Frances Separovic

Journal article  |  2017  |  MOLECULES

A One-Pot Chemically Cleavable Bis-Linker Tether Strategy for the Synthesis of Heterodimeric Peptides

Nitin A Patil, Julien Tailhades, John A Karas, Frances Separovic, John D Wade, Mohammed Akhter Hossain

Journal article  |  2016  |  ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

Total Chemical Synthesis of an Intra-A-Chain Cystathionine Human Insulin Analogue with Enhanced Thermal Stability

John A Karas, Nitin A Patil, Julien Tailhades, Marc-Antoine Sani, Denis B Scanlon, Briony E Forbes, James Gardiner, Frances Separovic, John D Wade, Mohammed Akhter Hossain

Journal article  |  2016  |  ANGEWANDTE CHEMIE-INTERNATIONAL EDITION

An enzyme-responsive controlled release system based on a dual-functional peptide

X Li, S Burger, AJ O'Connor, L Ong, JA Karas, SL Gras

Journal article  |  2016  |  Chemical Communications

2-Nitroveratryl as a Photocleavable Thiol-Protecting Group for Directed Disulfide Bond Formation in the Chemical Synthesis of Insulin

John A Karas, Denis B Scanlon, Briony E Forbes, Irina Vetter, Richard J Lewis, James Gardiner, Frances Separovic, John D Wade, Mohammed A Hossain

Journal article  |  2014  |  CHEMISTRY-A EUROPEAN JOURNAL

One-step radiosynthesis of 4-nitrophenyl 2-[F-18]fluoropropionate ([F-18]NFP); improved preparation of radiolabeled peptides for PET imaging

Mohammad B Haskali, Peter D Roselt, John A Karas, Wayne Noonan, Christian W Wichmann, Andrew Katsifis, Rodney J Hicks, Craig A Hutton

Journal article  |  2013  |  JOURNAL OF LABELLED COMPOUNDS & RADIOPHARMACEUTICALS

Chemical Synthesis of a Fluorescent IGF-II Analogue

Jade M Cottam, Denis B Scanlon, John A Karas, Antonio N Calabrese, Tara L Pukala, Briony E Forbes, John C Wallace, Andrew D Abell

Journal article  |  2013  |  INTERNATIONAL JOURNAL OF PEPTIDE RESEARCH AND THERAPEUTICS

Total chemical synthesis of a heterodimeric interchain bis-lactam-linked Peptide: application to an analogue of human insulin-like Peptide 3.

John Karas, Fazel Shabanpoor, Mohammed Akhter Hossain, James Gardiner, Frances Separovic, John D Wade, Denis B Scanlon

Journal article  |  2013  |  International Journal of Peptides

Nonreducible cystine isosteres represent important peptide design elements in that they can maintain a near-native tertiary confor..

Synthetic dityrosine-linked beta-amyloid dimers form stable, soluble, neurotoxic oligomers

W Mei Kok, Jade M Cottam, Giuseppe D Ciccotosto, Luke A Miles, John A Karas, Denis B Scanlon, Blaine R Roberts, Michael W Parker, Roberto Cappai, Kevin J Barnham, Craig A Hutton

Journal article  |  2013  |  CHEMICAL SCIENCE

Modulation of Conotoxin Structure and Function Is Achieved through a Multienzyme Complex in the Venom Glands of Cone Snails

Helena Safavi-Hemami, Dhana G Gorasia, Andrew M Steiner, Nicholas A Williamson, John A Karas, Joanna Gajewiak, Baldomero M Olivera, Grzegorz Bulaj, Anthony W Purcell

Journal article  |  2012  |  Journal of Biological Chemistry

A Cyclic Peptide Inhibitor of ApoC-II Peptide Fibril Formation: Mechanistic Insight from NMR and Molecular Dynamics Analysis

Michael DW Griffin, Levi Yeung, Andrew Hung, Nevena Todorova, Yee-Foong Mok, John A Karas, Paul R Gooley, Irene Yarovsky, Geoffrey J Howlett

Journal article  |  2012  |  JOURNAL OF MOLECULAR BIOLOGY

Microwave Synthesis of Prion Protein Fragments up to 111 Amino Acids in Length Generates Biologically Active Peptides

John A Karas, Martin Boland, Cathryn Haigh, Vanessa Johanssen, Andrew Hill, Kevin Barnham, Steven Collins, Denis Scanlon

Journal article  |  2012  |  International Journal of Peptide Research and Therapeutics

Misfolded conformers of the prion protein are aetiologically implicated in neurodegenerative conditions termed prion diseases (als..

Gallium-68 Complex of a Macrobicyclic Cage Amine Chelator Tethered to Two Integrin-Targeting Peptides for Diagnostic Tumor Imaging

Michelle T Ma, Oliver C Neels, Delphine Denoyer, Peter Roselt, John A Karas, Denis B Scanlon, Jonathan M White, Rodney J Hicks, Paul S Donnelly

Journal article  |  2011  |  BIOCONJUGATE CHEMISTRY

Total Synthesis of the Antifungal Depsipeptide Petriellin A

Marianne M Sleebs, Denis Scanlon, John Karas, Rani Maharani, Andrew B Hughes

Journal article  |  2011  |  JOURNAL OF ORGANIC CHEMISTRY

We report the solid-phase total synthesis of the antifungal highly modified cyclic depsipeptide petriellin A. The synthesis confir..

Macrobicyclic Cage Amine Ligands for Copper Radiopharmaceuticals: A Single Bivalent Cage Amine Containing Two Lys(3)-bombesin Targeting Peptides

Michelle T Ma, Margaret S Cooper, Rowena L Paul, Karen P Shaw, John A Karas, Denis Scanlon, Jonathan M White, Philip J Blower, Paul S Donnelly

Journal article  |  2011  |  INORGANIC CHEMISTRY

Embryonic Toxin Expression in the Cone Snail Conus victoriae PRIMED TO KILL OR DIVERGENT FUNCTION?

Helena Safavi-Hemami, William A Siero, Zhihe Kuang, Nicholas A Williamson, John A Karas, Louise R Page, David MacMillan, Brid Callaghan, Shiva Nag Kompella, David J Adams, Raymond S Norton, Anthony W Purcell

Journal article  |  2011  |  Journal of Biological Chemistry

Predatory marine cone snails (genus Conus) utilize complex venoms mainly composed of small peptide toxins that target voltage- and..

Synthesis of Peptide Sequences Derived from Fibril-Forming Proteins

Denis B Scanlon, John A Karas

Book Chapter  |  2011  |  Methods in Molecular Biology

Functional and Structural Diversification of the Anguimorpha Lizard Venom System

Bryan G Fry, Kelly Winter, Janette A Norman, Kim Roelants, Rob JA Nabuurs, Matthias JP van Osch, Wouter M Teeuwisse, Louise van der Weerd, Judith E Mcnaughtan, Hang Fai Kwok, Holger Scheib, Laura Greisman, Elazar Kochva, Laurence J Miller, Fan Gao, John Karas, Denis Scanlon, Feng Lin, Sanjaya Kuruppu, Chris Shaw, et al.

Journal article  |  2010  |  MOLECULAR & CELLULAR PROTEOMICS

Versatile New Bis(thiosemicarbazone) Bifunctional Chelators: Synthesis, Conjugation to Bombesin(7-14)-NH2, and Copper-64 Radiolabeling

Brett M Paterson, John A Karas, Denis B Scanlon, Jonathan M White, Paul S Donnelly

Journal article  |  2010  |  INORGANIC CHEMISTRY

Novel Venom Proteins Produced by Differential Domain-Expression Strategies in Beaded Lizards and Gila Monsters (genus Heloderma)

Bryan G Fry, Kim Roelants, Kelly Winter, Wayne C Hodgson, Laura Griesman, Hang Fai Kwok, Denis Scanlon, John Karas, Chris Shaw, Lily Wong, Janette A Norman

Journal article  |  2010  |  Molecular Biology and Evolution

Effects of mutation on the amyloidogenic propensity of apolipoprotein C-II60-70 peptide

Nevena Todorova, Andrew Hung, Simon M Maaser, Michael DW Griffin, John Karas, Geoffrey J Howlett, Irene Yarovsky

Journal article  |  2010  |  PHYSICAL CHEMISTRY CHEMICAL PHYSICS

Mass Spectral Identification of Vc1.1 and Differential Distribution of Conopeptides in the Venom Duct of Conus victoriae. Effect of Post-Translational Modifications and Disulfide Isomerisation on Bioactivity

A Townsend, BG Livett, J-P Bingham, H-T Truong, JA Karas, P O'Donnell, NA Williamson, AW Purcell, D Scanlon

Journal article  |  2009  |  International Journal of Peptide Research and Therapeutics

Aromatic residues in the C-terminal helix of human apoC-I mediate phospholipid interactions and particle morphology

Patrick F James, Con Dogovski, Renwick CJ Dobson, Michael F Bailey, Kenneth N Goldie, John A Karas, Denis B Scanlon, Richard AJ O'Hair, Matthew A Perugini

Journal article  |  2009  |  Journal of Lipid Research

A central role for venom in predation by Varanus komodoensis (Komodo Dragon) and the extinct giant Varanus (Megalania) priscus

Bryan G Fry, Stephen Wroe, Wouter Teeuwisse, Matthias JP van Osch, Karen Moreno, Janette Ingle, Colin McHenry, Toni Ferrara, Phillip Clausen, Holger Scheib, Kelly L Winter, Laura Greisman, Kim Roelants, Louise van der Weerd, Christofer J Clemente, Eleni Giannakis, Wayne C Hodgson, Sonja Luz, Paolo Martelli, Karthiyani Krishnasamy, et al.

Journal article  |  2009  |  Proceedings of the National Academy of Sciences of the United States of America

Rapid Optimization of a Peptide Inhibitor of Malaria Parasite Invasion by Comprehensive N-Methyl Scanning

Karen S Harris, Joanne L Casey, Andrew M Coley, John A Karas, Jennifer K Sabo, Yen Yee Tan, Olan Dolezal, Raymond S Norton, Andrew B Hughes, Denis Scanlon, Michael Foley

Journal article  |  2009  |  Journal of Biological Chemistry

Solid-phase synthesis of homodimeric peptides: preparation of covalently-linked dimers of amyloid beta peptide

W Mei Kok, Denis B Scanlon, John A Karas, Luke A Miles, Deborah J Tew, Michael W Parker, Kevin J Barnham, Craig A Hutton

Journal article  |  2009  |  Chemical Communications

A new bifunctional chelator for copper radiopharmaceuticals: a cage amine ligand with a carboxylate functional group for conjugation to peptides

Michelle T Ma, John A Karas, Jonathan M White, Denis Scanlon, Paul S Donnelly

Journal article  |  2009  |  Chemical Communications

Comprehensive N-Methyl Scanning of a Potent Peptide Inhibitor of Malaria Invasion into Erythrocytes Leads to Pharmacokinetic Optimization of the Molecule

Denis Scanlon, Karen S Harris, Andrew M Coley, John A Karas, Joanne L Casey, Andrew B Hughes, Michael Foley

Conference Proceedings  |  2008  |  International Journal of Peptide Research and Therapeutics

Siah up-regulates the Hif-1alpha hypoxic response pathway: Siah binding peptides coupled to CPPs inhibit Siah activity and demonstrate proof of concept that Siah is a viable anti-tumor drug target

Denis Scanlo, Colin House, John Karas, Andreas Moeller, Christina Wong, Mira Liu, Ze'ev Ronai, David Bowtell

Conference Proceedings  |  2008  |  JOURNAL OF PEPTIDE SCIENCE

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  |  Journal of Medicinal Chemistry