periplasmatische

Periplasmatic, or periplasmic, refers to the periplasm, the region between the inner cytoplasmic membrane and the outer membrane in most Gram-negative bacteria. This compartment is distinct from the cytoplasm and the external environment and contains a gel-like matrix with solutes, enzymes, and structural components such as a thin layer of peptidoglycan.

The periplasm houses a variety of proteins involved in nutrient acquisition, envelope biogenesis, and environmental sensing. Enzymes such as hydrolases and other processing proteins operate here, along with periplasmic binding proteins that participate in transport systems (for sugars, amino acids, and other substrates). The space also contains chaperones and enzymes that assist in protein folding and the formation of disulfide bonds, contributing to the maturation of many envelope and periplasmic proteins. Peptidoglycan remodeling and assembly steps linked to the inner membrane can occur in this compartment, coordinating cell wall synthesis with envelope integrity.

Functionally, the periplasm serves as a site for substrate processing before uptake, a staging area for outer membrane protein assembly, and a barrier-modulating space that helps bacteria cope with stress and toxins. It also plays a role in initial interactions with the environment and in antibiotic resistance; for example, beta-lactamases located in the periplasm can degrade beta-lactam antibiotics before they reach their penicillin-binding targets.

In Gram-positive bacteria, there is no true periplasmic space between two membranes, as they lack an outer membrane. The term periplasmatic is primarily applied to Gram-negative organisms.