1. Basic Information
- 英文名称：PKA Substrate
- 中文名称：蛋白激酶 A 底物
- 氨基酸序列：Gly-Arg-Thr-Gly-Arg-Arg-Asn-Ser-Ile
- 单字母序列：GRTGRRNSI
- 三字母序列：Gly-Arg-Thr-Gly-Arg-Arg-Asn-Ser-Ile
- 分子量：1015.13
- 分子式：C39H74N20O12
- 等电点：未明确提及
- CAS 号：121932 - 31 - 8
供应商：上海楚肽生物科技有限公司
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2. Structure Information
The PKA Substrate is a nine - amino - acid phosphorylatable peptide. The specific arrangement of the amino acids Gly - Arg - Thr - Gly - Arg - Arg - Asn - Ser - Ile in the peptide chain gives it a unique structure. The presence of arginine residues, which are positively charged at physiological pH, may play important roles in its interaction with PKA. The serine residue is the site that can be phosphorylated by protein kinase A, and the overall structure of the peptide likely positions this serine in an accessible location for the kinase enzyme to act upon.
3. Mechanism of Action and Research Progress
3.1 Mechanism of Action
PKA Substrate is a potent and selective substrate peptide of protein kinase A (PKA). Protein kinase A is a cyclic adenosine monophosphate (cAMP) - dependent enzyme. When cAMP levels increase in the cell, it binds to the regulatory subunits of PKA, causing a conformational change that releases the catalytic subunits. These catalytic subunits then phosphorylate target proteins, including the PKA Substrate. The PKA Substrate is phosphorylated at the serine residue (Ser) in its sequence (GRTGRRNSI). This phosphorylation event can be used as a read - out for PKA activity. In research settings, the phosphorylation of the PKA Substrate by PKA can be detected using various methods such as radiolabeling (using radioactive phosphate), Western blotting with phospho - specific antibodies, or mass spectrometry to identify the phosphorylated peptide.
3.2 Research Progress
- Enzymatic Assays：PKA Substrate has been widely used in enzymatic assays to study the activity of PKA. For example, it has been used as a peptide substrate for plasmodium cyclic guanosine monophosphate (GMP) - dependent protein kinase in enzymatic assay and inhibition assay. By measuring the rate of phosphorylation of the PKA Substrate, researchers can determine the activity of the kinase and also study the effects of various inhibitors or activators on kinase activity.
- In Vitro Phosphorylation Assays：It has also been used as a positive control in in vitro protein kinase A (PKA) phosphorylation assays. In these assays, researchers can test the functionality of PKA preparations, optimize reaction conditions for phosphorylation reactions, and compare the activity of different PKA isoforms or PKA from different sources.
4. Solubility and Storage
- Solubility：The solubility of PKA Substrate can vary depending on the solvent. Generally, it may be soluble in aqueous buffers such as phosphate - buffered saline (PBS) at appropriate pH values. Some organic solvents may also be used for solubilization, but care must be taken as they may affect the peptide's integrity or the subsequent assays in which it is used.
- Storage：It is recommended to store PKA Substrate at low temperatures, typically at - 20 °C or - 80 °C. This helps to prevent degradation of the peptide, which could occur due to proteolytic enzymes (if present), oxidation, or other chemical reactions. When stored properly, the peptide can maintain its activity and integrity for an extended period.
5. Related Peptides
- PKA Inhibitor Fragment (6 - 22) Amide：This is a peptide inhibitor of cAMP - dependent protein kinase (PKA). Its sequence (in 3 - letter code) is Thr - Tyr - Ala - Asp - Phe - Ile - Ala - Ser - Gly - Arg - Thr - Gly - Arg - Arg - Asn - Ala - Ile - NH2, and in 1 - letter code is TYADFIA S GRTGRR NAI - NH2. It has a reported affinity of 1.7 nM for PKA. While the PKA Substrate is phosphorylated by PKA, this inhibitor binds to PKA and blocks its activity, providing an interesting contrast in the study of PKA function.
6. Related Literature
[1] The use of PKA Substrate in enzymatic assays to study PKA activity has been described in many research papers. For example, papers that focus on the regulation of PKA in different cell types or biological processes may use PKA Substrate as a tool. A relevant study could be: AuthorLastName, AuthorFirstName. "Title of the Paper." JournalName, Volume(Issue), Pages (Year). DOI: xxxxxxxx (if available). However, without more specific research topics in mind, it's difficult to provide more detailed and targeted literature references.
