http://www.mdpi.com/journal/marinedrugs/special_issues/marine-peptides/ Dear Colleagues, The marine environment is a vast source of natural products. The biodiversity found in the oceans is remarkable and it has only begun to be explored recently, when compared with terrestrial habitats. The molecular variety associated with this biodiversity represents a challenge for drug discovery. Nevertheless, screening and pharmacological evaluation of marine natural products as potential drug leads has taken a giant leap in the past two decades. As a result, the first drug of marine origin has obtained approval by the FDA on December 31st 2004. Prialt, a peptide (an ω-conotoxin) isolated from a cone snail (Conus magus), has been approved for the treatment of chronic pain as a morphine replacement therapy and it is the most powerful painkiller known to date. This landmark event is evidence that a new wave of “Drugs from the Sea” with novel pharmacologies for the treatment of an array of diseases and conditions is on its way. This issue of Marine Drugs is dedicated to “Marine Peptides”. Whether these compounds are ribosomally-expressed, such as the conotoxins and sea anemone toxins, or enzymatically-produced peptides, they are of great interest as drug leads and for drug development. We hope that the manuscripts here included will cover several aspects of recent developments within the field. Prof. Dr. Frank Mari Guest Editor Submission All manuscripts should be submitted to marinedrugs@mdpi.com with a copy to the Guest Editor. Manuscripts can be submitted until the deadline. Papers will be published continuously (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website. Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are refereed through a peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Marine Drugs is an international peer-reviewed Open Access monthly journal published by MDPI. Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this Open Access journal is 1400 CHF per accepted paper. http://www.mdpi.com/1660-3397/9/1/71/ The first synthesis of a naturally occurring tetrapeptide cyclo-(isoleucyl-prolyl-leucyl-alanyl) has been achieved using a solution-phase technique via coupling of dipeptide segments Boc-l-Pro-l-Leu-OH and l-Ala-l-Ile-OMe. Deprotection of the linear tetrapeptide unit and its subsequent cyclization gave a cyclopeptide, identical in all aspects to the naturally occurring compound. Bioactivity results indicated the antifungal and antihelmintic potential of the synthesized peptide against pathogenic dermatophytes and earthworms. http://www.mdpi.com/1660-3397/9/1/71/ Thu, 30 Dec 2010 00:00:00 CET Marine Drugs 2010-12-30 9 1 Article 71 81 1660-3397 Toward the Synthesis and Biological Screening of a Cyclotetrapeptide from Marine Bacteria 2010-12-30 doi: 10.3390/md9010071 Rajiv Dahiya Hemendra Gautam http://www.mdpi.com/1660-3397/8/8/2223/ Microorganisms secrete into their extracellular environment numerous compounds that are required for their survival. Many of these compounds could be of great interest for biotechnology applications and their genes used in synthetic biology design. The secreted proteins and the components of the translocation systems themselves can be scrutinized in-depth by the most recent proteomic tools. While the secretomes of pathogens are well-documented, those of non-pathogens remain largely to be established. Here, we present the analysis of the exoproteome from the marine bacterium Ruegeria pomeroyi DSS-3 grown in standard laboratory conditions. We used a shotgun approach consisting of trypsin digestion of the exoproteome, and identification of the resulting peptides by liquid chromatography coupled to tandem mass spectrometry. Three different proteins that have domains homologous to those observed in RTX toxins were uncovered and were semi-quantified as the most abundantly secreted proteins. One of these proteins clearly stands out from the catalogue, representing over half of the total exoproteome. We also listed many soluble proteins related to ABC and TRAP transporters implied in the uptake of nutrients. The Ruegeria pomeroyi DSS-3 case-study illustrates the power of the shotgun nano-LC-MS/MS strategy to decipher the exoproteome from marine bacteria and to contribute to environmental proteomics. http://www.mdpi.com/1660-3397/8/8/2223/ Thu, 29 Jul 2010 00:00:00 CEST Marine Drugs 2010-07-29 8 8 Article 2223 2239 1660-3397 In-Depth Analysis of Exoproteomes from Marine Bacteria by Shotgun Liquid Chromatography-Tandem Mass Spectrometry: the Ruegeria pomeroyi DSS-3 Case-Study 2010-07-29 doi: 10.3390/md8082223 Joseph Alexander Christie-Oleza Jean Armengaud