STRUCTURAL STUDIES OF PROTEINS THAT INHIBIT APOPTOSIS

描述：本提案的目标是执行结构和 P35是一种抑制细胞凋亡的病毒蛋白。 细胞凋亡是一种自然发生的细胞自杀过程， 正常的有机体发育和组织稳态。 之甚少 已知细胞凋亡和细胞死亡中的畸变的调节 它可以引发许多疾病。 所有不同的信号 利用一种新的半胱氨酸， 蛋白酶来传递凋亡程序。 这条共同的途径使它 治疗剂调节的最有吸引力的靶点。 因此，我们认为， 更好地理解半胱氨酸蛋白酶的结构力学 功能和抑制是必需的。 杆状病毒表达35 kDa的 抑制参与执行死亡的半胱氨酸蛋白酶的蛋白质 信号了 杆状病毒P35是一种普遍的和非常有效的抑制剂， 细胞凋亡，并可阻断哺乳动物、鼠和昆虫细胞中细胞凋亡 线 P35抑制细胞凋亡的能力，在这样的不同范围内， 由不同信号诱导的生物表明，它的作用是在一个 凋亡途径中进化保守的步骤。 杆状病毒P35 定义了一类新的蛋白酶抑制剂， 信息. P35首先被半胱氨酸蛋白酶切割，然后抑制 形成一个紧密结合的死端复合物。 x射线质量 生长了P35晶体，得到了一种重原子衍生物。 功能丧失增强的P35的详细X射线结构分析 突变结构将揭示P35阻断细胞凋亡的机制。 另外的见解将获得通过分析晶体结构的 切割的P35与半胱氨酸蛋白酶复合。 这座建筑将提供 新的信息和线索的机制，蛋白酶，以及新的 凋亡抑制水平。 新的基本原理在函数上获得 P35也可能导致抗病毒化合物。

DESCRIPTION: The objectives of this proposal are to perform structural and mechanistic analysis on P35 a viral protein that inhibits apoptosis. Apoptosis is a naturally occurring process of cellular suicide that is vital to normal organismal development and tissue homeostasis. Very little is known about the regulation of apoptosis and aberrations in the cell death program can commence the onset of many diseases. All the different signals that trigger the cell death program utilize a new class of cysteine proteases to transmit the apoptosis program. This common pathway makes it the most attractive target for regulation by therapeutic agents. Therefore, a better understanding on the structural mechanics of the cysteine protease function and inhibition is required. The baculovirus expresses a 35 kDa protein that inhibits the cysteine proteases involved in executing the death signal. Baculovirus P35 is a general and very effective suppressor of apoptosis and can block apoptosis in mammalian, murine, and insect cell lines. The ability of P35 to suppress apoptosis in such a diverse range of organisms induced by different signals suggests that it acts at an evolutionarily conserved step in the apoptotic pathway. Baculovirus P35 defines a new class of protease inhibitors for which there is no structural information. P35 is first cleaved by the cysteine protease then inhibits the enzyme by forming a tightly bound dead-end complex. X-ray quality crystals of P35 have been grown and one heavy atom derivative obtained. Detailed x-ray structural analysis of P35 augmented with loss-of-function mutant structures will reveal the mechanism by which P35 blocks apoptosis. Additional insights will be gained by analyzing the crystal structure of cleaved P35 complexed with a cysteine protease. This structure will furnish new information and clues on the mechanism of the proteases as well as new levels of apoptotic inhibition. The new fundamentals gained on the function of P35 could also lead to anti-viral compounds.