Enzymatic clickable functionalization of peptides via computationally engineered peptide amidase

Efficient production of peptidylglycine α-hydroxylating monooxygenase in yeast for protein C-terminal functionalization

Peptidylglycine α-hydroxylating monooxygenase (PHM) is pivotal for C-terminal amidation of bioactive peptides in animals, offering substantial potential for customized protein synthesis. However, efficient PHM production has been hindered by the complexity of animal cell culture and the absence of glycosylation in bacterial hosts. Here, we demonstrate the recombinant expression of Caenorhabditis elegans PHM in the yeast Pichia pastoris, achieving a remarkable space-time yield of 28.8 U/L/day. This breakthrough surpasses prior PHM production rates and eliminates the need for specialized cultivation equipment or complex transfection steps. Mass spectrometry revealed N-glycosylation at residue N182 of recombinant CePHM, which impacts the enzyme's activity as indicated by biochemical experiments. To showcase the utility of CePHM, we performed C-terminal amidation on ubiquitin at a substrate loading of 30 g/L, a concentration meeting the requirements for pharmaceutical peptide production. Overall, this work establishes an efficient PHM production method, promising advancements in scalable manufacturing of C-terminally modified bioactive peptides and probe proteins.

Traceless enzymatic protein synthesis without ligation sites constraint

Protein synthesis and semisynthesis offer immense promise for life sciences and have impacted pharmaceutical innovation. The absence of a generally applicable method for traceless peptide conjugation with a flexible choice of junction sites remains a bottleneck for accessing many important synthetic targets, however. Here we introduce the PALME (protein activation and ligation with multiple enzymes) platform designed for sequence-unconstrained synthesis and modification of biomacromolecules. The upstream activating modules accept and process easily accessible synthetic peptides and recombinant proteins, avoiding the challenges associated with preparation and manipulation of activated peptide substrates. Cooperatively, the downstream coupling module provides comprehensive solutions for sequential peptide condensation, cyclization and protein N/C-terminal or internal functionalization. The practical utility of this methodology is demonstrated by synthesizing a series of bioactive targets ranging from pharmaceutical ingredients to synthetically challenging proteins. The modular PALME platform exhibits unprecedentedly broad accessibility for traceless protein synthesis and functionalization, and holds enormous potential to extend the scope of protein chemistry and synthetic biology.

Rationally designed peptide-conjugated gold/platinum nanosystem with active tumor-targeting for enhancing tumor photothermal-immunotherapy

Because of the tumor heterogeneity, poor therapeutic outcome is obtained while the conventional treatments, such as surgery, radiotherapy, or chemotherapy are utilized alone. Herein, combinational therapy strategies have been introduced to solve this problem. Photothermal therapy (PTT) as a non-invasive thermal therapeutic manner has attracting enormous attentions not only for the effective inhibition in primary tumors, but also for producing tumor-associated antigens from ablated tumor cell residues which exhibit the feasibility to enhance the therapeutic outcome of immunotherapy. Here, we report the construction and application of Au@Pt-based nanosystem with rationally designed peptide (LyP-1-PLGVRG-^DPPA-1, LM^DP) conjugation for cancer photothermal-immunotherapy. The obtained Au@Pt-LM^DP nanosystem can serve as a matrix metalloproteinase (MMP) activated tumor targeting agents for effective photothermal therapy together with immune checkpoint blockade immunotherapy by the on-demand release of a D-peptide antagonist of programmed cell death-ligand 1 (PD-L1). The PA imaging demonstrates its effective accumulation in the tumor region by the activated tumor targeting moiety derived from the LM^DP. Moreover, in vivo anti-tumor studies reveal that Au@Pt-LM^DP nanosystem can effectively eliminate primary tumors via PTT, and further stimulate the activation of cytotoxic T lymphocytes by PD-L1 immune checkpoint blockage, result in inhibiting the growth of distal tumors and alleviating tumor metastasis. The present study provides a promising strategy for the combination treatment of advanced cancer and obtains a valuable therapeutic outcome in tumor photothermal-immunotherapy.