# Chemoenzymatic synthesis of glycosylated and sulfated CCR5 N-terminal peptide library

> **NIH NIH R15** · DORDT COLLEGE · 2022 · $350,916

## Abstract

Co-localization of Tyrosine (Tyr) sulfation and O-glycosylation (CSOG) is an emerging global
pattern of post-translational modifications (PTMs). CSOG is the major PTM pattern on the N-
terminal peptide of CC chemokine receptor 5 (CCR5). CCR5 is involved in critical human
diseases such as cancers and inflammatory diseases, and the N-terminal peptide of CCR5 is
essential for the binding between CCR5 and its ligands. The access to sulfated and
glycosylated N-terminal peptides of CCR5 (CCR5-SGNTPs) and any other peptides with CSOG
is hindered by diversified patterns of glycosylation and sulfation, lability of sulfation, and
complex sugar structures. This proposal aims to develop efficient chemoenzymatic methods for
synthesizing glycopeptides containing O-glycans and Tyr sulfation. Therefore, we are aiming to
efficiently synthesize CCR5-SGNTPs to build up the access to CCR5-SGNTPs and further
provide new clues for related biomedical research. Lability of sulfate group during synthesis and
complexity of sugar structures are the major obstacles to the achievement of the library of
CCR5-SGNTPs. We provide a novel and efficient chemoenzymatic approach, merging two well-
studied synthetic methodologies to overcome the obstacles. One of the two methodologies is
solid-phase site-selective sulfation, and the other one is chemoenzymatic synthesis of
glycopeptides. Site-selective sulfation with divergently protected Tyrs can efficiently build
diversified sulfation patterns, and chemoenzymatic synthesis of glycopeptides can synthesize
glycopeptides with complex sugar structures in high regio- and stereo-selectivity with high
fidelity. Notably, the mild conditions (slightly basic) of glycosyltransferases catalyzed reactions
are ideal for keeping the integrity of the labile sulfate group. Glycosylated-amino acids (GAAs)
with core sugars and Fmoc-Tyrs with divergent protecting groups can be synthesized efficiently
with current synthetic methodologies. Then the two classes of building blocks will be selectively
incorporated into solid phase peptide synthesis (SPPS) to obtain protected sulfated and
glycosylated peptides. After removal of protecting groups, glycosyltransferases will be used to
extend the core sugars to generate larger and more complex glycopeptides following
biosynthetic pathways. After binding study of the synthesized library, detailed information about
how the two PTMs co-regulate binding processes will be obtained. Moreover, a peptide library
with structure-defined CCR5-SGNTPs will provide standards for proteomics and glycomics
research of CCR5-SGNTPs.

## Key facts

- **NIH application ID:** 10360095
- **Project number:** 1R15GM144930-01
- **Recipient organization:** DORDT COLLEGE
- **Principal Investigator:** Hailiang Joshua Zhu
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $350,916
- **Award type:** 1
- **Project period:** 2022-01-01 → 2023-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10360095

## Citation

> US National Institutes of Health, RePORTER application 10360095, Chemoenzymatic synthesis of glycosylated and sulfated CCR5 N-terminal peptide library (1R15GM144930-01). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10360095. Licensed CC0.

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