We study the reliability of the lateral manipulation of a single Cu adatom on a Cu(111) surface with single-atom, dimer and trimer apex tips using both semiempirical and first-principles simulations. The dependence of the manipulation reliability on tip height is investigated. For the single-atom apex tip the manipulation reliability increases monotonically with decreasing tip height. For the dimer and trimer apex tips the manipulation reliability is greatly improved compared to that for the single-atom apex tip over a certain tip-height range. Two kinds of mechanism are found responsible for this improvement. One is the so-called enhanced interaction mechanism in which the lateral tip-adatom interaction in the manipulation direction is improved. The other is the suspended atom mechanism in which the relative lateral trapping ability of the tip is improved due to the strong vertical attraction of the tip on the adatom. Both mechanisms occur in the manipulations with the trimer apex tip, while in those with the dimer apex tip only the former is effective. Moreover, we present a method to realize reversible vertical manipulation of a single atom on a Cu(111) surface with the trimer apex tip, based on its strong vertical and lateral attraction on the adatom.
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http://dx.doi.org/10.1088/0957-4484/19/33/335710 | DOI Listing |
Cell Rep
January 2025
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA; Division of Viral Products, Center for Biologics Evaluation and Research, Food and Drug Administration, Silver Spring, MD 20993, USA. Electronic address:
Broadly neutralizing antibodies (bNAbs) targeting the apex of the HIV-1-envelope (Env) trimer comprise the most potent category of HIV-1 bNAbs and have emerged as promising therapeutics. Here, we investigate the development of the HIV-1 apex-directed PGT145-PGDM1400 antibody lineage and report cryo-EM structures at 3.4 Å resolution of PGDM1400 and of an improved PGT145 variant (PGT145-R100aS), each bound to the BG505 Env trimer.
View Article and Find Full Text PDFComput Struct Biotechnol J
December 2024
Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA.
HIV-1 infection is initiated by the interaction between the gp120 subunit in the envelope (Env) trimer and the cellular receptor CD4 on host cells. This interaction induces substantial structural rearrangement of the Env trimer. Currently, static structural information for prefusion-closed trimers, CD4-bound prefusion-open trimers, and various antibody-bound trimers is available.
View Article and Find Full Text PDFNPJ Vaccines
December 2024
Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA, USA.
Eliciting broadly neutralizing antibodies that protect against diverse HIV-1 strains is a primary goal of AIDS vaccine research. We characterized Ab1456 and Ab1271, two heterologously-neutralizing antibodies elicited in non-human primates by priming with an engineered V3-targeting SOSIP Env immunogen and boosting with increasingly native-like SOSIP Envs derived from different strain backgrounds. Structures of Env trimers in complex with these antibodies revealed V3 targeting, but on conformational states of Env distinct from the typical closed, prefusion trimeric SOSIP structure.
View Article and Find Full Text PDFPLoS Pathog
September 2024
Consortium for HIV/AIDS Vaccine Development (CHAVD), The Scripps Research Institute, La Jolla, California, United States of America.
Microorganisms
August 2024
Department of Virology III, National Institute of Infectious Diseases, Musashimurayama-shi 208-0011, Tokyo, Japan.
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