Where can I find the protein concentration?

The protein concentration of each product is listed on the Certificate of Analysis. This value is determined for each individual lot and reflects the actual concentration (mg/mL) of the material you received.

Where can I find the recommended storage conditions?

Storage conditions are listed on both the product datasheet and the Certificate of Analysis. These recommendations are based on internal stability assessments and are intended to maintain protein integrity and activity.

Where can I find reconstitution instructions for lyophilized products?

If your product is supplied lyophilized, recommended reconstitution instructions are provided on the product datasheet. These instructions outline the suggested solvent and handling tips to ensure optimal recovery and stability.

How should I store my product after reconstitution?

Unless otherwise stated on the datasheet or COA, we recommend aliquoting reconstituted material and storing at –80 °C to avoid repeated freeze–thaw cycles, which may impact protein stability and activity.

Cathepsin G

Name: Cathepsin G
SKU: 16-14-030107-50UG
Availability: InStock

CatG, CTSG

An azurophilic granule serine protease that, as a component of the innate immune system, enzymatically degrades collagen, proteoglycans, and chemokines. Uncontrolled Cat G activity is implicated in emphysema and cystic fibrosis lung damage, as well as rheumatoid arthritis severity.

Purity: ≥95% (SDS-PAGE)

Source: Human Neutrophils

Molecular Weight: 23.5 kDa

Form: Lyophilized

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Product Description

Role of protein in biology

Cathepsin G (CTSG), encoded by the CTSG gene on chromosome 14q11.2, is a neutrophil-derived serine protease stored in azurophilic granules. Structurally, it features a catalytic triad (His57, Asp102, Ser195) that enables dual chymotryptic and tryptic activities in humans due to a primate-specific Glu226 substitution. Beyond degrading collagen and proteoglycans, CTSG processes chemokines (e.g., CCL15, CXCL5) into potent chemoattractants, activates matrix metalloproteinases (MMP-2, MMP-9) to drive tissue remodeling, and generates angiotensin II from angiotensinogen via cleavage at Phe8 and Tyr4. This angiotensin II production enhances vascular permeability by disrupting endothelial cadherins and tight junctions, contributing to edema in sepsis and acute lung injury.

Clinically, CTSG is implicated in emphysema through synergistic elastin degradation with neutrophil elastase and proteinase 3, and in rheumatoid arthritis (RA) by recruiting monocytes via chemerin activation and exacerbating synovial inflammation. Elevated CTSG levels correlate with RA severity and serve as a diagnostic biomarker. In cystic fibrosis, dysregulated CTSG promotes lung matrix breakdown, while in Alzheimer’s disease, it cleaves amyloid-β precursors.

Common research uses

Therapeutically, CTSG inhibitors like α1-antichymotrypsin and investigational monoclonal antibodies attenuate vascular leakage and inflammation in preclinical models. Its dual protease activities and role in immune cell recruitment position CTSG as a promising target for autoimmune and degenerative disorders.

Common uses include proteolytic enzyme studies, cardiovascular research, In Vitro Assay standards, immune system research, and pulmonary disease research.