# Minimal Protein Affinity Tags

> **NIH NIH R15** · TRINITY UNIVERSITY · 2021 · $428,303

## Abstract

PROJECT SUMMARY
 Biomedical science relies heavily on methods for attaching ligand binding sites to proteins. Such affinity tags
are essential for protein affinity purification, for improving protein solubility, and for adding functionality to
proteins such as fluorescent labels or sites for chemical modification. The proposed research aims to develop
a general method for modifying target proteins using affinity tags that comprise only 1-2 amino acid residues.
The minimal affinity tags are bound site-specifically and with high-affinity by small (1-2 kDa) synthetic
receptor that can be conjugated to solid supports and small molecules. The receptors are stable and functional
in physiologic conditions, including serum, and proteins bound to these receptors can be released easily upon
the addition of small molecule competitors. The proposed aims include: 1) further optimizing dipeptide
recognition sites; 2) investigating the binding of synthetic receptors to target sites that already exist in protein
pharmaceuticals and other bioactive peptides and proteins; 3) installing minimal affinity tags into recombinant
proteins and protein pharmaceuticals; and 4) developing functional derivatives of the synthetic receptor to
bring functionality to the target proteins. Such minimal affinity tags will add substantial function to target
proteins while having minimal impact on their structure and activity. The proposed work builds on the rules
for selective, high-affinity recognition of peptides and proteins by cucurbit[n]urils established in the
undergraduate research lab of the PI. Many research groups have developed applications built on these rules,
and we anticipate that the proposed research will establish a core competency that should facilitate existing
biomedical applications and inspire new ones.

## Key facts

- **NIH application ID:** 10203453
- **Project number:** 1R15GM141708-01
- **Recipient organization:** TRINITY UNIVERSITY
- **Principal Investigator:** ADAM Robert URBACH
- **Activity code:** R15 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $428,303
- **Award type:** 1
- **Project period:** 2021-09-01 → 2025-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10203453

## Citation

> US National Institutes of Health, RePORTER application 10203453, Minimal Protein Affinity Tags (1R15GM141708-01). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/10203453. Licensed CC0.

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