membranlose

Membranlose is an adjective used in biology to denote structures or particles that lack a surrounding lipid membrane. The term is commonly applied in virology to describe viruses that do not possess a lipid envelope; such nonenveloped viruses have a protein capsid surrounding their genome and interact with host cells mainly through capsid proteins. Examples of membranlose viruses include many members of the Adenoviridae, Picornaviridae (such as rhinoviruses and enteroviruses), Caliciviridae, Reoviridae, and Parvoviridae. The absence of a membrane influences stability outside the host and routes of entry.

In cell biology, membranlose can describe compartments or assemblies that are not enclosed by a lipid bilayer. This includes cytosolic protein complexes and biomolecular condensates such as the nucleolus, stress granules, and P-bodies, which arise through phase separation. These structures are dynamic and can rapidly assemble or disassemble in response to cellular conditions. Their lack of a surrounding membrane allows relatively unrestricted exchange with the cytosol and enables rapid concentration or sequestration of specific molecules.

Terminology and scope: membranlose is used primarily in German-language scientific literature. It is important to distinguish membranlose from membrane-bound or organelle-associated structures, which are enclosed by lipid membranes. The concept highlights the diversity of cellular organization, illustrating how life can compartmentalize biochemistry both with and without membranes. See also: cell membrane, lipid bilayer, nonenveloped viruses, biomolecular condensates.