Corona viruses have traditionally been associated with mild upper respiratory tract infections throughout the world. In the fall of 2002, a new corona virus emerged in Asia causing severe viral pneumonia, i.e., severe acute respiratory syndrome (SARS). Nearly a decade following the SARS epidemic, a new corona virus causing severe viral pneumonia has emerged, i.e., middle east respiratory syndrome (MERS). Since the initial case of MERS-CoV occurred in June of 2012 in Saudi Arabia there have been 688 confirmed cases and 282 deaths in 20 countries. Although both SARS and MERS are caused by corona viruses, SARS was characterized by efficient human transmission and relatively low mortality rate. In contrast, MERS is relatively inefficiently transmitted to humans but has a high mortality rate. Given the potential overlap in presentation and manifestation, it is important to understand the clinical and epidemiologic differences between MERS, SARS and influenza.
MERS-CoV has caused outbreaks of a SARS-like illness with high case fatality rate. The reports of its person-to-person transmission through close contacts have raised a global concern about its pandemic potential. Here we characterize the six-helix bundle fusion core structure of MERS-CoV spike protein S2 subunit by X-ray crystallography and biophysical analysis. We find that two peptides， HR1P and HR2P， spanning residues 998–1039 in HR1 and 1251–1286 in HR2 domains， respectively, can form a stable six-helix bundle fusion core structure， suggesting that MERS-CoV enters into the host cell mainly through membrane fusion mechanism. HR2P can effectively inhibit MERS-CoV replication and its spike protein-mediated cell–cell fusion. Introduction of hydrophilic residues into HR2P results in significant improvement of its stability， solubility and antiviral activity. Therefore, the HR2P analogues have good potential to be further developed into effective viral fusion inhibitors for treating MERS-CoV infection .
Recently, the Ebola virus in Africa has caused serious consequences. Antiviral drugs research and development is more and more important, polypeptide of antiviral drugs is also a kind of promising products. For example, Cationic antimicrobial peptides (AMPs) and host defense peptides (HDPs) show vast potential as peptide-based drugs. Great effort has been made in order to exploit their mechanisms of action, aiming to identify their targets as well as to enhance their activity and bioavailability. Emphasis will be given to their biochemical features, selectivity against extra targets, and molecular mechanisms. Peptides which possess antitumor activity against different cancer cell lines will be discussed, as well as peptides which inhibit virus replication, focusing on their applications for human health, animal health and agriculture, and their potential as new therapeutic drugs .
Karebay Biochem (www.karebaybio.com) has a professional team devoted to peptide products synthesis and development. We offer high-quality peptide synthesis products for sale around the world, including over 1,000 catalog peptides, and nearly 100 pharmaceutical peptides and cosmetic peptides products.  Cunha CB, Middle East respiratory syndrome (MERS): A new zoonotic viral pneumonia. Virulence. 2014 Aug 15;5(6):650-654.  Lu L, et al. Structure-based discovery of Middle East respiratory syndrome coronavirus fusion inhibitor. Nat Commun. 2014;5:3067.  Kelly C. L. Mulder, et al. Current scenario of peptide-based drugs: the key roles of cationic antitumor and antiviral peptides. Front. Microbiol., 31 October 2013.