repeat

Tau Peptide (275-305), also known as the R2 domain fragment, represents the second repeat unit of the microtubule-binding domain of the Alzheimer's tau peptide. Tau Peptide (275-305) is considered crucial in determining the biochemical characteristics of the complete tau protein.

Survivin (baculoviral inhibitor of apoptosis IAP repeat-containing protein-5) is a member of the IAP gene family, which has been implicated in both inhibitions of apoptosis and mitosis regulation1. Survivin is one of the most uniformly up-regulated genes

IRBP acetate(211426-18-5 free base) (Interphotoreceptor Retinoid Binding Protein Fragment IRBP) is a 20-residue peptide, which is a major pathogenic epitope. It exists in the first homologous repeat of interstitial visual pigment Binding Protein peptide (IRBP 161-180) and can induce post-uveitis (EAU).

Hsp70-derived octapeptide acetate (Hsp70-derived octapeptide acetate) is a group of tetratricopeptide repeat (TPR)-containing proteins has been shown to interact with the C-terminal domain of the 70 kDa heat-shock cognate protein (hsc70). In the present study, the effect of the TPR-containing proteins, including the C-terminus of hsc70-interacting protein (CHIP), TPR1 and human glutamine-rich TPR-containing protein (hSGT), on refolding of luciferase by DnaJ and hsc70 was investigated.

SARS-CoV-2-IN-34 (S-20-1) is a broad-spectrum pan-coronavirus (CoV) fusion inhibitor that penetrates the blood-brain barrier and exhibits extensive inhibitory activity against both pseudotyped and authentic SARS-CoV-2, as well as pseudotyped variants of concern (VOCs). It shows high affinity for the receptor-binding domain (RBD) in the S1 and the heptad repeat 1 (HR1) domain in the S2 of the SARS-CoV-2 spike (S) protein, making it a valuable tool for infection research [1].

PHF6 (VQIVYK), a sequence within the third microtubule-binding repeat region of the tau protein, initiates the aggregation of the full-length tau protein through its self-assembly capabilities [1].

C34 peptide, also referred to as HR2, is a biologically active peptide integral to the helical region of HIV's gp41 and is specifically the C-terminal heptad repeat 2 (HR2), denoted as the C helix or C peptide. It functions as a potent inhibitor of HIV-1 fusion, thereby impeding the virus's entry into cells via membrane fusion.

Tat-NTS peptide, a cell-penetrating compound, comprises the HIV-1 Tat protein transduction domain fused with a 10-amino acid sequence (residues 228-237) from the repeat III domain of annexin A1, serving as a nuclear translocation signal (NTS). This peptide hinders the interaction between annexin A1 and importin β, obstructing annexin A1's nuclear entry in primary mouse hippocampal neurons. Tat-NTS effectively prevents apoptosis triggered by glucose-oxygen deprivation and reperfusion in these neurons. When administered in vivo at a dosage of 10 mg/kg, it significantly reduces infarct size, minimizes neuronal apoptosis, and improves navigation performance in the Morris water maze test for mice subjected to ischemia-reperfusion injury via middle cerebral artery occlusion (MCAO).

LRRKtide, a peptide substrate for leucine-rich repeat kinase 2 (LRRK2)—an enzyme often mutated in Parkinson's disease patients—corresponds to amino acids 550-564 of the membrane-organizing extension spike protein (moesin). It serves to identify inhibitors of LRRK2.

BRC4wt, an acetylated peptide originating from the BRC4 repeat within human BRCA2 (1521-1536), acts as an inhibitor of the BRCA2 and RAD51 protein-protein interaction. When linked to the cationic cell-penetrating peptide (Arg)9, it effectively shortens DNA replication tract lengths and diminishes the frequency of homologous repair of camptothecin-induced DNA damage in vitro. Additionally, BRC4wt enhances the efficacy of the poly(ADP-ribose) polymerase (PARP) inhibitor olaparib in inducing cell death in HeLa human cervical cancer and U2OS human osteosarcoma cells, albeit it does not affect non-cancerous hTERT RPE-1, MRC-5, or MCF-10A cells.

Interphotoreceptor Retinoid Binding Protein Fragment (IRBP 161-180) is a 20-residue peptide that acts as a major pathogenic epitope, located in the first homologous repeat of interstitial visual pigment Binding Protein, and can induce post-uveitis (EAU).

A group of tetratricopeptide repeat (TPR)-containing proteins has been shown to interact with the C-terminal domain of the 70 kDa heat-shock cognate protein (hsc70). In the present study, the effect of the TPR-containing proteins, including the C-terminus

QPH-FR is a quinoa peptide and acts as an inhibitor of the G protein-coupled receptor 5 (LGR5) that is abundant in leucine repeat sequences. By binding to LGR5, QPH-FR competitively inhibits the formation of the LGR5/RSPO1 complex. This interaction leads to the ubiquitination of FZD receptors by RNF43/ZNRF3, thereby inhibiting the Wnt/β-catenin signaling pathway and exerting stem cell suppression.

GCO-(GPO)10-GCOG is a polypeptide containing GPO repeat sequences, exhibiting a collagen-like single collagen triple-helix structure. The cross-linked triple-helix GCO-(GPO)10-GCOG can form collagen-related peptide (CRP) mimetics that closely bind Yersinia adhesin YadA. YadA mediates the adhesion of the human intestinal pathogen Yersinia enterocolitica to collagen and other extracellular matrix components, potentially disrupting host processes mediated by endogenous collagen-binding proteins. GCO-(GPO)10-GCOG is useful for studying YadA-related infections.

FNIII14 is derived from the 14th type III-like (FN-III) repeat sequence of the fibronectin (FN) molecule. It inhibits cellular adhesion to the extracellular matrix (ECM) by inducing β1-integrin (β1integrin) to shift from an active to an inactive state, blocking integrin-mediated signaling. With its antifibrotic and anticancer properties, FNIII14 is useful for research in metabolic diseases, organ fibrosis, and malignancies.

EK1 is a peptide-based coronavirus (CoV) fusion inhibitor that exhibits broad-spectrum inhibitory activity against various coronaviruses. EK1 demonstrates significantly enhanced pan-coronavirus fusion inhibitory activity and effectively suppresses SARS-CoV-2. It can form a stable six-helix bundle (6HB) structure with short α-hCoV and long β-hCoV N-terminal heptad repeat sequences.