Endo S Glycosidase: Key Enzyme for Antibody Glycoengineering and Glycomics Research

1. Concept

Endo‑β‑N‑acetylglucosaminidase S (Endo S, EC 3.2.1.96) is a highly specific glycoside hydrolase from Streptococcus pyogenes, family GH85. It selectively cleaves the core GlcNAc‑β1,4‑GlcNAc glycosidic bond of biantennary complex‑type N‑glycans at the Asn297 site of the IgG Fc region. Its strict substrate specificity makes it an indispensable tool for antibody glycosylation analysis, glycoengineering, and biopharmaceutical quality control.

2. Research Frontier

Antibody glycosylation critically determines effector functions such as ADCC, CDC, and half‑life. Endo S enables precise glycan removal and remodeling, supporting next‑generation antibody development, glycomics profiling, and therapeutic optimization. Engineered variants and immobilized formats further expand its use in high‑throughput and industrial applications.

3. Research Significance

Endo S bridges glycobiology and biopharmaceutical development:

• Enables site‑specific analysis of IgG Fc glycosylation
• Supports antibody glycan remodeling for improved efficacy
• Ensures batch consistency and quality control of antibody drugs
• Facilitates mechanistic studies of structure–function relationships
• Accelerates innovation in antibody‑based therapeutics and vaccines

[Image: Endo S workflow for antibody deglycosylation and glycan analysis]

4. Core Mechanisms & Research Methods

4.1 Molecular Properties

• Structure: (β/α)8 barrel catalytic fold; 136 kDa recombinant enzyme
• Catalytic dyad: Glu233 / Asp167 (acid–base catalysis)
• Kinetics: Km = 2.5 ± 0.3 μM; kcat = 15 ± 2 s⁻¹
• Optimal conditions: pH 5.0–7.0 (peak 5.5); 37°C
• Stability: Ca²⁺ enhances stability; robust in denaturants

4.2 Catalytic Mechanism

1. Recognition: Positively charged residues bind glycan termini
2. Induced fit: Loop 1 closure forms active catalytic pocket
3. Hydrolysis: Glu233 protonates glycosidic oxygen; Asp167 stabilizes transition state
4. Release: Cleaved glycans and deglycosylated antibody separate

4.3 Key Applications

Antibody Glycoengineering

• Removes Fc glycans for functional studies
• Enables afucosylation to boost ADCC 3–5 fold
• Supports design of next‑generation therapeutic antibodies

Glycomics & Glycoproteomics

• “Endo S + HILIC‑UPLC‑MS” workflow for high‑sensitivity profiling
• Detection limit: 0.1 μg IgG; CV < 5%
• Compatible with serum, cell lysates, and purified samples

Biopharmaceutical Quality Control

• Glycoform consistency validation
• Inter‑batch comparability and stability testing

4.4 Engineered Variants

• D165Q: Expands activity toward high‑mannose substrates
• Thermostable mutants: Tm +15°C
• Immobilized Endo S: Reusable for >50 batches

[Image: Comparison of IgG before and after Endo S deglycosylation]

5. ANT BIO PTE. LTD. Product Empowerment

ANT BIO PTE. LTD. provides high‑performance Endo S and supporting reagents for reliable glycosylation research and antibody engineering.

Core Product Performance

表格

Standard Protocol

• Reaction: 1–20 μg IgG + 1× Buffer + Endo S; 37°C, 1 h
• Termination: 85°C, 5 min
• Detection: SDS‑PAGE mobility shift; MS glycan analysis

6. Brand Mission

ANT BIO PTE. LTD. is a leading provider of premium life science reagents, focusing on high‑quality antibodies, recombinant proteins, assay kits, and general laboratory reagents. We operate three specialized subbrands to cover full research workflows:

• Absin: General reagents, buffers, and ELISA kits
• Starter: High‑performance antibodies and functional magnetic beads
• UA: Recombinant proteins for research, immunization, and validation

We are committed to delivering stable, reliable, and traceable reagents to accelerate breakthroughs in glycobiology, antibody engineering, and biopharmaceutical development.

7. Related Product List

• Endo S glycosidase (recombinant, high‑purity)
• Glycosylation buffer systems (Absin)
• PNGase F and other glycosidases (Absin)
• Antibody Fc region–specific antibodies (Starter)
• Recombinant IgG and glycoprotein standards (UA)
• WB, MS, and UPLC‑compatible reagents (Absin)

Brand Promotion Copy

ANT BIO PTE. LTD. – Empowering Scientific Breakthroughs

At ANTBIO, we are committed to advancing life science research through high-quality, reliable reagents and comprehensive solutions. Our specialized sub-brands (Absin, Starter, UA) cover a full spectrum of research needs, from general reagents and kits to antibodies and recombinant proteins. With a focus on innovation, quality, and customer-centricity, we strive to be your trusted partner in unlocking scientific mysteries and driving medical progress. Explore our product portfolio today and elevate your research to new heights.