Medarametla, P. | Search bioRxiv

bioRxiv2026

Bioengineered recombinant kisspeptins with extended half-life exhibit novel peripheral function in a large-animal model

Kisspeptins are the small peptide products encoded by the KISS1 gene and physiologically exist in various isoforms of variable length. They are the central regulators of reproduction, being a prominent driver of GnRH hormone secretion. Additionally, they have emerged as an important peripheral therapeutic target for many metabolic diseases like diabetes, obesity, and polycystic ovary syndrome (PCOS). Despite their therapeutic potential, their utility is severely limited by their short half-life. We have rationally bioengineered two versions of native kisspeptins, which we named HSK-1 and HSK-2. HSK-1 (8kDa) and HSK-2 (13kDa) are derived from the fusion of the albumin-binding ZAG domain from Streptococcus zooepidemicus with KP-10 and KP-52 versions of kisspeptins (KPs), respectively. In vitro assays confirmed that the proteins were functionally active and triggered downstream signalling. Molecular dynamics simulations of the proteins revealed their structural features relative to the native kisspeptin isoforms. Both molecules demonstrated stable receptor engagement, and ligand-induced conformational changes were observed, suggesting receptor activation. HSK proteins demonstrated an extended half-life and mostly acted peripherally in young animals. They reduced peripheral luteinizing hormone levels in young animals, likely representing a previously unrecognized mode of peripheral kisspeptin action. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=77 SRC="FIGDIR/small/703727v1_ufig1.gif" ALT="Figure 1"> View larger version (22K): org.highwire.dtl.DTLVardef@7b02fdorg.highwire.dtl.DTLVardef@13da0org.highwire.dtl.DTLVardef@174d467org.highwire.dtl.DTLVardef@124c653_HPS_FORMAT_FIGEXP M_FIG C_FIG

biochemistry↗

bioRxiv2020

Structural characterization of LsrK to target quorum sensing and comparison between X-ray and homology model

Quorum sensing is being investigated as an alternative therapeutic strategy in antibacterial drug discovery to combat bacterial resistance. LsrK is an autoinducer-2 kinase, playing a key role in the phosphorylation of autoinducer-2 (AI-2) signalling molecules involved in quorum sensing. Inhibiting LsrK could result in reduced pathogenicity by interfering with the quorum sensing signalling. Previously, we have generated homology models to identify LsrK inhibitors using structure-based virtual screening and successfully found the first class of LsrK inhibitors. While conducting these studies, the crystal structure of LsrK was released providing us an opportunity to inspect the reliability and quality of our models. Structural analysis of crystal structure and homology models revealed the consistencies of constructed models with crystal structure in the structural fold and binding site. Further, binding characteristics and conformational changes are investigated using molecular dynamics. These simulations provided us insights into the protein function and flexibility that need to be considered during the structure-based drug design studies targeting LsrK.

biophysics↗