Snail mucus is not just a slimy substance that snails produce to move around and protect themselves. It is also a rich source of proteins, some of which are unknown to science. A new study published in Nature Communication has analyzed the mucus of a common garden snail and found that it contains three different types of secretions, each with its own function and composition.
Snail Mucus: A Multi-Purpose Material
Snails are mollusks that belong to the class Gastropoda, which includes more than 60,000 species of land and aquatic snails and slugs. Snails have a muscular foot that secretes mucus to help them glide over surfaces, adhere to substrates, and prevent dehydration. Snail mucus is also known for its cosmetic, medicinal, and antimicrobial properties.
The researchers in the new study focused on the mucus of Cornu aspersum, also known as the brown garden snail or the petit-gris. This species is widely distributed around the world and is used in beauty products and as a delicacy. The researchers collected mucus samples from different parts of the snail’s body and analyzed them using mass spectrometry, a technique that identifies molecules based on their mass and charge.
They found that the snail mucus contained more than 70 proteins, including enzymes, mucins, lectins, and matrix proteins. Mucins are glycoproteins that give mucus its viscosity and lubricity. Lectins are proteins that bind to carbohydrates and mediate cell-cell interactions. Matrix proteins are proteins that provide structural support and regulate cell functions.
The researchers also discovered that about one-third of the proteins in the snail mucus had no similarity with any known proteins in the databases they searched. These novel proteins could have unique functions and applications that are yet to be explored.
Snail Mucus: A Three-in-One Secretion
The researchers further classified the snail mucus into three types of secretions based on their location and function:
- Skin mucus: This type of mucus covers the entire body of the snail and acts as a barrier against dehydration and pathogens. It contains high levels of mucins, lectins, and matrix proteins that form a hydrated gel-like network. It also contains enzymes that can degrade foreign molecules and peptides that have antimicrobial activity.
- Adhesive mucus: This type of mucus is produced by the sole of the foot and allows the snail to stick to various surfaces. It contains high levels of matrix proteins that form cross-linked networks that can withstand mechanical stress. It also contains lectins that can bind to specific carbohydrates on the surface of plants or rocks.
- Lubricating mucus: This type of mucus is also produced by the sole of the foot but has a different composition from the adhesive mucus. It contains low levels of matrix proteins and high levels of mucins that reduce friction and allow the snail to slide smoothly over surfaces.
The researchers found that the adhesive mucus and the lubricating mucus had very similar protein profiles but differed in their sugar content. The adhesive mucus had more complex sugars than the lubricating mucus, which could explain their different properties. The researchers also noted that the adhesive mucus and the lubricating mucus came from the same part of the snail but had opposite functions.
Snail Mucus: A Bioinspired Resource
The study provides new insights into the molecular complexity and diversity of snail mucus and its potential applications in biotechnology and medicine. Snail mucus is already used in cosmetics, moisturizers, anti-aging creams, wound care treatments, and antimicrobials. However, there are still many open questions about the structure and function of snail mucus and its proteins.
The researchers hope that their study will inspire further research on snail mucus and its novel proteins. They also suggest that snail mucus could be used as a model system to study how animals adapt to different environments by modifying their secretions.
“Everyone is fascinated and disgusted by mucus. However, most people don’t realize just how complex and elegant these secretions are,” said the study’s principal investigator Adam Braunschweig, who is a faculty member with the Nanoscience Initiative at the Advanced Science Research Center at the CUNY Graduate Center (CUNY ASRC) and a professor of chemistry and biochemistry at the Graduate Center and Hunter College.
Snail mucus is not only a fascinating biological material but also a bioinspired resource of significant promise.