Phosphorylase Kinase β-Subunit Fragment (420-436) is a peptide fragment (430-436) derived from the β-Subunit of phosphorylase kinase. Phosphorylase kinase, a serine/threonine-specific protein kinase, plays a crucial role in the activation of glycogen phosphorylase for the release of glucose-1-phosphate from glycogen[1].
7-oxo Staurosporine is an antibiotic originally isolated from S. platensis with diverse biological activites. It inhibits PKC, PKA, phosphorylase kinase, EGFR, and c-Src in vitro (IC50s = 9, 26, 5, 200, and 800 nM, respectively). 7-oxo Staurosporine induces cell cycle arrest in the G2/M phase in human leukemia K562 cells with a minimal effective dose (MED) of 30 ng/ml. It is cytotoxic to P388 mouse leukemia cells that are resistant and susceptible to doxorubicin . 7-oxo Staurosporine inhibits growth of the mycelial, but not yeast form of C. albicans, C. krusei, C. tropicalis, and C. lusitaniae (MICs = 3.1-25 μg/ml). It increases sphingomyelin synthesis in CHO-K1 cells when used at a concentration of 50 nM.
The cyanobacterium Nodularia spumigena often contaminates the drinking water of rural communities in developing countries and accumulates in mussels, flounder, and cod from the northern Baltic Sea. Nodularin is a hepatotoxic monocylic pentapeptide produced by the N. spumigena. It is a potent inhibitor of protein phosphatase types 1 (PP1) and 2A (PP2A), exhibiting IC50 values of 1.8 and 0.026 nM, respectively. PP2B is inhibited to a lesser extent with an IC50 of 1.8 μM. No apparent inhibitory effect is observed with PP2C, alkaline phosphatase, acid phosphatase, insulin receptor tyrosine kinase, protein kinase A, phosphorylase kinase, or protein kinase C.
Myelin Basic Protein (MHP4-14) TFA 是一种合成肽,包含髓鞘碱性蛋白的残基4-14,是一种非常有选择性的 PKC 底物 (Km=7 μM)。Myelin Basic Protein TFA 不被环腺苷酸依赖性蛋白激酶、酪蛋白激酶 I 和 II、Ca2+/钙调素依赖性蛋白激酶 II 或磷酸化酶激酶磷酸化,可常规用于测定粗组织提取物中低背景的蛋白激酶 C。