02523nas a2200205 4500008004100000022001400041245007500055210006900130260000800199300001200207490000800219520183200227653002702059653002302086653003102109100002002140700002702160700002002187856011002207 2022 eng d a0022-263100aMolecular mechanisms underlying caveolin-1 mediated membrane curvature0 aMolecular mechanisms underlying caveolin1 mediated membrane curv cJUN a225-2360 v2553 a

Caveolin-1 is one of the main protein components of caveolae that acts as a mechanosensor at the cell membrane. The interactions of caveolin-1 with membranes have been shown to lead to complex effects such as curvature and the clustering of specific lipids. Here, we review the emerging concepts on the molecular interactions of caveolin-1, with a focus on insights from coarse-grain molecular dynamics simulations. Consensus structural models of caveolin-1 report a helix-turn-helix core motif with flanking domains of higher disorder that could be membrane composition dependent. Caveolin-1 appears to be mainly surface-bound and does not embed very deep in the membrane to which it is bound. The most interesting aspect of caveolin-1 membrane binding is the interplay of cholesterol clustering and membrane curvature. Although cholesterol has been reported to cluster in the vicinity of caveolin-1 by several approaches, simulations show that the clustering is maximal in membrane leaflet opposing the surface-bound caveolin-1. The intrinsic negative curvature of cholesterol appears to stabilize the negative curvature in the opposing leaflet. In fact, the simulations show that blocking cholesterol clustering (through artificial position restraints) blocks membrane curvature, and vice versa. Concomitant with cholesterol clustering is sphingomyelin clustering, again in the opposing leaflet, but in a concentration-dependent manner. The differential stress due to caveolin-1 binding and the inherent asymmetry of the membrane leaflets could be the determinant for membrane curvature and needs to be further probed. The review is an important step to reconcile the molecular level details emerging from simulations with the mesoscopic details provided by state of the art experimental approaches. [GRAPHICS] .

10aCholesterol clustering10aMembrane curvature10aProtein-lipid interactions1 aPrakash, Shikha1 aMalshikare, Hrushikesh1 aSengupta, Durba uhttps://library.ncl.res.in/content/molecular-mechanisms-underlying-caveolin-1-mediated-membrane-curvature03087nas a2200157 4500008004100000022001400041245006400055210006300119260000800182300001400190490000800204520257800212100002702790700002002817856009202837 2025 eng d a0006-349500aMembrane remodeling by the caveolin-1 8s oligomeric complex0 aMembrane remodeling by the caveolin1 8s oligomeric complex cOCT a3206-32160 v1243 a

Caveolin-1 is a scaffolding protein crucial for the formation of caveolae, specialized membrane structures that are involved in diverse cellular processes such as endocytosis, mechanosensing, and lipid regulation. Recently, a unique structure of the 8S oligomeric complex of caveolin-1 was resolved by cryoelectron microscopy, providing a foundational basis for understanding its molecular mechanisms. In this study, we probe the membrane interactions of the oligomeric caveolin-1 complex in membrane lipid bilayers and vesicles. We performed coarse-grained molecular dynamics simulations to delineate the interactions of the palmitoylated and nonpalmitoylated caveolin-1 with multicomponent membranes. During the simulations, the caveolin-1 complex binds to the membranes, partially to one of the leaflets in a shallow monotopic arrangement. A remodeling of the lipids in its vicinity of the complex was observed in both vesicles and planar bilayers. However, the caveolin-1 complex binds to vesicles without inducing any significant change to the curvature, whereas it appears to induce increased curvature in the planar bilayers leading to the formation of highly curved nanodomains. Cholesterol and phosphoserine lipid enrichment, hallmarks of caveolin-1 binding, were observed in a membrane topology-dependent manner. The differential cholesterol clustering observed between vesicles and bilayers highlights the curvature-dependent nature of caveolin-1-mediated lipid organization. Our work highlights the dual significance of lipid organization and membrane topology in the functional dynamics of caveolin-1, shedding light on its role in inducing and sensing membrane curvature, which is pivotal for various cellular processes. SIGNIFICANCE The rather unanticipated experimental structure of the oligomeric complex of caveolin-1 has opened up multiple questions such as how caveolin-1 interacts with cell membranes and how curvature can be induced or stabilized by a relatively flat protein complex. Here, we identify the molecular mechanisms underlying membrane curvature by caveolin-1 using coarse-grained molecular dynamics simulations. We show that the caveolin-1 complex can bind in a shallow monotopic arrangement and initiate clustering cholesterol and phosphoserine lipids. In vesicles, caveolin-1 binding does not lead to differences in curvature, but binding to planar bilayer leads to the formation of highly curved nanodomains. Our work is an important step to identify novel mechanisms of caveolin-1 stabilized or induced membrane curvature.

1 aMalshikare, Hrushikesh1 aSengupta, Durba uhttps://library.ncl.res.in/content/membrane-remodeling-caveolin-1-8s-oligomeric-complex01875nas a2200181 4500008004100000022001400041245010400055210006900159260000800228300001700236490000700253520121700260100002701477700002101504700002401525700002001549856012401569 2026 eng d a1359-734500aMechanistic principles of antimicrobial peptides uncovered by charge density-based machine learning0 aMechanistic principles of antimicrobial peptides uncovered by ch cFEB aPMID 96108380 v623 a

Antimicrobial peptides (AMPs) are emerging as potent alternatives to conventional antibiotics, yet their diverse nature due to divergent mechanisms of action hinders rational design. Here, we present an electrostatics-stratified computational framework that uncovers key physicochemical principles governing AMP activity. Experimentally validated peptides were grouped by average charge per residue (i.e., the charge/length of the peptide) and analyzed through integrated sequence-, structure-, and chemistry-based descriptors. Distinct molecular signatures emerged across electrostatic regimes: low-charge/length peptides rely on amphipathic organization via structural compactness, whereas the intermediate-charge/length peptides exhibit balanced hydrophobicity and electrostatics. The high-charge peptides couple strong cationic attraction with lipophilicity and tryptophan anchoring to mainly disrupt membranes. Interestingly, hydrophobic moment, which is a measure of the amphipathicity, is found to be important in all three classes of AMPs. This study identifies distinguishing features of AMP sub-groups and suggests design guidelines for developing selective and potent next-generation AMPs.

1 aMalshikare, Hrushikesh1 aPriyakumar, Deva1 aChatterjee, Prathit1 aSengupta, Durba uhttps://library.ncl.res.in/content/mechanistic-principles-antimicrobial-peptides-uncovered-charge-density-based-machine