Chemoinformatic

**Chapter 4**

**Abstract**

bioactivity scores

**1. Introduction**

**59**

Conceptual DFT as a Helpful

Chemoinformatics Tool for the

Study of the Clavanin Family of

A well-behaved model chemistry previously validated for the study of the chemical reactivity of peptides was considered for the calculation of the molecular properties and structures of the clavanin family of antimicrobial marine peptides. A methodology based on conceptual density functional theory (CDFT) was chosen for the determination of the reactivity descriptors. The molecular active sites were associated with the active regions of the molecules related to the nucleophilic and electrophilic Fukui functions. Finally, the drug-likenesses and the bioactivity scores for the clavanin peptides were predicted through a homology methodology relating them with the calculated reactivity descriptors, while other properties like the pKas

**Keywords:** clavanin, conceptual DFT, chemical reactivity, drug-likeness features,

Bioactive peptides are promising novel drug leads that may fill the gap between small molecules and larger biologicals. This is reflected by a multitude of recent peptide discovery and development approaches. However, their use as therapeutic lead molecules is challenged by their typically poor stability and lack of oral bioavailability. This is often due to the linear nature of peptides that not only exhibit free ends but multiple cleavage sites that are readily recognized by enzymes that degrade peptide chains into inactive fragments or single amino acids [1–10]. The marine environment is considered Earth's last frontier of exploration. In fact, a common belief is that just less than 5% of the vast and rich marine environment has been explored. Our seas and oceans represent a very unknown resource for the discovery of novel organisms, (bio)products, (bio)processes, and for the development of bioinspired synthetic drugs. Recent advances in genetics and other (bio)molecular techniques are providing all necessary tools to access these stilluntapped marine resources on a larger scale and, consequently, enable exploitation

were determined following a methodology developed by our group.

of the true promise of the blue biotechnology [11].

Antimicrobial Marine Peptides

*Norma Flores-Holguín, Juan Frau*

*and Daniel Glossman-Mitnik*
