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Recombinant Proteins
Product List
CST9 Human
Cystatin 9 Human Recombinant
Recombinant CST9 Human, produced in E. coli, is a single, non-glycosylated polypeptide chain comprising 152 amino acids (29-159). With a molecular weight of 17.2 kDa, CST9 is fused to a 21 amino acid His-tag at the N-terminus and purified using proprietary chromatographic techniques.
Shipped with Ice Packs 
Cat. No.
BT25363
Source
E.coli.
Appearance
A clear, colorless solution that has been sterilized by filtration.
CSTA Human, Active
Cystatin-A Human Recombinant, Active
Recombinant Human Cystatin A, produced in E. coli, is a single, non-glycosylated polypeptide chain composed of 118 amino acids (1-98a.a.) with a molecular weight of 13.1 kDa. It features a 20 amino acid His tag at the N-terminus and undergoes purification using proprietary chromatographic methods.
Shipped with Ice Packs
Cat. No.
BT25451
Source
Escherichia Coli.
Appearance
A clear solution that has been sterilized by filtration.
CSTA Human, His
Cystatin A Human Recombinant, His tag
Produced in E. coli, CSTA is a single, non-glycosylated polypeptide chain consisting of 118 amino acids (with the active protein encompassing amino acids 1-98). Its molecular mass is 13.1kDa. The CSTA protein includes a 20 amino acid His-tag fused to the N-terminus and undergoes purification using proprietary chromatographic techniques.
Shipped with Ice Packs
CSTB Human
Cystatin B Human Recombinant
Recombinant human CSTB, fused with a 20 amino acid His-Tag at its N-terminus, is produced in E. coli. This process yields a single, non-glycosylated polypeptide chain comprising 118 amino acids (specifically, amino acids 1 through 98) with a molecular weight of 13 kDa.
Shipped with Ice Packs
Cat. No.
BT25635
Source
Escherichia Coli.
Appearance
A clear, colorless solution that has been sterilized by filtration.
Introduction
Definition and Classification
Cystatins are a family of cysteine protease inhibitors that play a crucial role in regulating proteolytic activity within cells. They are classified into three main types:
- Type 1 Cystatins (Stefins): These are primarily intracellular proteins found in the cytosol of various cell types .
- Type 2 Cystatins: These are mainly extracellular secreted polypeptides, found in most body fluids .
- Type 3 Cystatins (Kininogens): These are multidomain proteins, with mammalian representatives including high-molecular-mass and low-molecular-mass kininogens .
Biological Properties
Cystatins exhibit several key biological properties:
- Inhibitory Activity: They inhibit cysteine proteases such as cathepsins and legumain, which are involved in protein degradation .
- Expression Patterns: Cystatins are expressed in a wide variety of tissues and body fluids .
- Tissue Distribution: They are found in virtually all tissues, with specific types being more prevalent in certain tissues. For example, cystatin C is found in high concentrations in the brain and kidneys .
Biological Functions
Cystatins serve several primary biological functions:
- Regulation of Protease Activity: They regulate the activity of cysteine proteases, preventing excessive proteolysis .
- Immune Response: Cystatins modulate immune responses by influencing the activity of cathepsins involved in antigen presentation and cytokine production .
- Pathogen Recognition: They play a role in recognizing and responding to pathogens by inhibiting proteases that pathogens use to invade host tissues .
Modes of Action
Cystatins interact with other molecules and cells through several mechanisms:
Regulatory Mechanisms
The expression and activity of cystatins are controlled by various regulatory mechanisms:
Applications
Cystatins have several applications in biomedical research and clinical practice:
Role in the Life Cycle
Cystatins play a role throughout the life cycle, from development to aging and disease:
- Development: They are involved in regulating protease activity during embryonic development and tissue remodeling .
- Aging: Changes in cystatin levels and activity have been associated with aging and age-related diseases .
- Disease: Dysregulation of cystatin activity is implicated in various diseases, including neurodegenerative disorders, cardiovascular diseases, and cancer .
