Utilizing 1,2-diaminocyclopropane-1,2-dicarboxylic acid (DACDC) as a tetrafunctional peptide linker is proposed and discussed on the basis of the ab initio second-order Moller-Plesset and density functional theory (DFT) theoretical studies. It is demonstrated that the DACDC molecule may form four peptide bonds with natural amino acids such as alanine and, as a consequence, two peptide chains might be connected to each other by the DACDC unit which in turn reveals the ability of DACDC to act as a new type of peptide linker-peptide clasp. (C) 2018 Elsevier B.V. All rights reserved.