Related Experiment Video
Updated: Oct 28, 2026

Constructing Thioether/Vinyl Sulfide-tethered Helical Peptides Via Photo-induced Thiol-ene/yne Hydrothiolation
Published on: August 1, 2018
Linear and SS cyclized radiopeptides for estrogen receptor targeting
Sonal Gupta1, Manoj Kumar2, Krishna Mohan Repaka3
1Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai, India; KET's V. G. Vaze College, Mumbai University, India.
Abstract:
Breast cancer is the most prevalent cancer globally, accounting for 18% of all cancers in women. Majority of breast cancers (75%) are associated with over-expression of estrogen receptors (ER). In this report, two ER-targeting peptides were synthesized manually on solid phase. The ER-affine pentapeptide motif LHRLL was conjugated with cell penetrating cationic amino acid sequence, RRRRK to obtain the peptide construct ERK (RRRRKILHRLLQDS-NH2) and a cyclic variant cERK (RRRRKCLHRCLQDS). The two peptides were conjugated with DOTA chelator and radiolabeled with Lu-177. [177Lu]Lu-DOTA-ERK and [177Lu]Lu-DOTA-cERK showed high binding affinity (~30 nM) towards human breast carcinoma MCF-7 cells. High cellular internalization was observed for the two radiopeptides. The cyclic variant, [177Lu]Lu-DOTA-cERK exhibited higher human serum stability and metabolic stability in mouse urine sample. Higher tumor uptake and tumor-to-organ ratios were presented by [177Lu]Lu-DOTA-cERK. This first attempt of evaluation of LXXLL motif radiopeptide will broaden the scope of synthesis of diverse ligands with improved biological profile.
Related Concept Videos
Directing Proteins to the Rough Endoplasmic Reticulum
Transducer Mechanism: Nuclear Receptors
About 48 different soluble family members of nuclear receptors are identified that can be divided into two main classes:
Transducer Mechanism: Enzyme-Linked Receptors
Major types that are helpful drug targets include:
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Modified-Release Drug Delivery Systems: Site-Targeted
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...

