亞基的生物化學(xué)：Biochemistry

　

2018-11-30 21:52:59 394 0

生物化學(xué)翻譯

To show that HAX-1 degradation is part of the apoptotic process and any involvement Omi may have， we used the ucf-101 inhibitor. ucf-101 is a specific inhibitor of the proteolytic activity of Omi and has been described previously (13). When... To show that HAX-1 degradation is part of the apoptotic process and any involvement Omi may have， we used the ucf-101 inhibitor. ucf-101 is a specific inhibitor of the proteolytic activity of Omi and has been described previously (13). When HK-2 cells were treated with cisplatin in the presence of ucf-101， the percentage of apoptotic cells decreased and the inhibitor significantly blocked HAX-1 degradation. This effect was more pronounced when a higher concentration of the inhibitor was used. To confirm the specificity of the inhibitor in this system and exclude the possibility that another protease rather than Omi is involved in HAX-1 cleavage， we used cell lines derived from mnd2 mice (9). The parent cell line (mnd2-MSCV) derived from mouse embryo fibroblasts has no detectable Omi proteolytic activity (9). The same cell line has been transfected with wild type human Omi cDNA (mnd2-MSCV-Omi) and expresses high levels of active Omi protein (14). We found that in mnd2-MSCV cells， when induced to undergo apoptosis with various stimuli， the number of apoptotic cells was very low. Furthermore， no detectable cleavage of HAX-1 was observed. This is in contrast with the mnd2-MSCV-Omi cells where apoptosis was robust， and HAX-1 levels were inversely proportional to the degree of apoptosis. This experiment clearly shows that Omi is solely responsible for HAX-1 cleavage， which is essential for apoptosis under the conditions used in these experiments. HAX-1 subcellular localization depends on cell type (21， 30) and has been reported to be present in the mitochondria， cytoplasm， or plasma membrane (10， 21， 22， 30). We performed subcellular fractionation to investigate where HAX-1 cleavage by Omi takes place. We found that， in HEK293 cells， HAX-1 was predominantly present in the mitochondria， and this localization did not change in response to apoptotic stimuli. This suggests that Omi can initiate apoptosis in the mitochondria by cleaving HAX-1 protein. This is in accord with a recent study that shows Omi can induce apoptosis in human neutrophils treated with TNF- without being released from the mitochondria (7). Although several studies clearly define HAX-1 as an anti-apoptotic protein， the mechanism of its function is unknown. HAX-1 has sequence similarity to Bcl-2 family of proteins (10， 22). 展開

2007-02-03 21:19:55 522 1

生物化學(xué)考點(diǎn)

農(nóng)林類

2011-11-22 08:48:23 398 2

生物化學(xué)判斷正誤題

等摩爾的D-ALa和L-ALa混合液，不能引起偏振光平面的偏轉(zhuǎn)()如果錯(cuò)誤理由是什么... 等摩爾的D-ALa和 L-ALa混合液，不能引起偏振光平面的偏轉(zhuǎn)() 如果錯(cuò)誤理由是什么 展開

2018-05-31 19:14:26 275 1

生物化學(xué)脂肪酸的β氧化名詞解釋

　

2012-12-30 03:36:48 467 3

求生物化學(xué)第三版的名詞解釋

　

2016-01-13 16:41:47 448 1

生物化學(xué)DNA的生物合成

生物化學(xué)DNA的生物合成dNTP dNMP dNDP 之間是什么關(guān)系？

2017-03-18 15:13:45 494 1

生物化學(xué)簡(jiǎn)答和名詞解釋

補(bǔ)考生物化學(xué)的的簡(jiǎn)答題和名詞解釋誰那里有比較全的請(qǐng)發(fā)下吧！ 馬上就要考試了~~~~~~~ Z好連答案也有

2010-04-22 02:04:19 516 2

生物化學(xué)有哪些內(nèi)容？

　

2010-09-18 11:29:04 663 1

生物化學(xué)中PL什么意思

　

2011-12-26 01:12:54 1665 4

多肽和蛋白質(zhì)的亞基著2概念有什么區(qū)別

　

2009-08-10 15:40:45 986 2

生物化學(xué)作業(yè) 名詞解釋 核酸的雜交?

　

2012-11-09 10:49:28 508 3

生物化學(xué)名詞解釋同工酶競(jìng)爭(zhēng)性YZ

　

2016-06-19 20:42:07 636 1

生物化學(xué)有哪三大代謝

　

2018-01-31 08:22:21 1769 2

生物化學(xué)做一下，謝謝了

一、選擇題1、構(gòu)成輔酶A的維生素有A、生物素B、泛酸C、VB1D、VB22、酶促反應(yīng)的特點(diǎn)是A、GX性B能觸發(fā)化學(xué)反應(yīng)的進(jìn)行C、提高反應(yīng)的活化能D、反應(yīng)前后酶的質(zhì)量不變3、具有生物活性的全... 一、選擇題 1、構(gòu)成輔酶A的維生素有 A、生物素 B、泛酸 C、VB1 D、VB2 2、酶促反應(yīng)的特點(diǎn)是 A、GX性 B能觸發(fā)化學(xué)反應(yīng)的進(jìn)行 C、提高反應(yīng)的活化能 D、反應(yīng)前后酶的質(zhì)量不變 3、具有生物活性的全酶，無輔助因子時(shí) A、有活性 B、無活性 C、無特異性 D、不易失活 4、米氏常數(shù)Km值 A、愈大，酶與底物親和力越高 B、愈小，酶與底物親和力越低 C、愈小，酶與底物親和力越大 D、大小與酶的濃度有關(guān) 5、酶原激活過程中，通常使酶原分子中 斷裂 A、氫鍵 B、疏水鍵 C、離子鍵 D、肽鍵 6、酶促反應(yīng)速度與下列因素成正比的是 A、溫度 B、PH值 C、酶濃度 D、底物濃度 7、缺乏維生素C將導(dǎo)致 A、壞血病 B、夜盲癥 C、貧血 D、瘌皮病 8、核苷酸合成時(shí)，需一碳基團(tuán)，轉(zhuǎn)移一碳基團(tuán)的輔酶是 A、四氫葉酸 B、NAD C、TPP D、生物素 9、有關(guān)同工酶的描述，其中不正確 A、來源可以不同 B、理化性質(zhì)相同 C、催化反應(yīng)相同 D、分子量可以不同 10、酶的競(jìng)爭(zhēng)性YZ特點(diǎn)是 A、YZ劑與酶的活性ZX結(jié)構(gòu)相似 B、YZ作用的強(qiáng)弱與YZ劑濃度的大小無關(guān) C、YZ劑濃度不受底物濃度的影響 D、YZ與酶作用的底物結(jié)構(gòu)相似 11、缺乏后，會(huì)導(dǎo)致腳氣病的維生素是 A、VB1 B、VB2 C、VC D、VPP 12、下列維生素中參與轉(zhuǎn)氨基的作用的 A、硫胺素 B、尼克酸 C、核黃素 D、磷酸吡哆醛 13、酶催化作用對(duì)能量的影響在于 A、增加產(chǎn)物能量水平 B、降低活化能 C、降低反應(yīng)物能量水平 D、降低反應(yīng)在自由能 14、下面關(guān)于蛋白酶的敘述正確的是 A、所有酶都是蛋白質(zhì) B、所有的酶都含有輔基或輔酶 C、都只能在體內(nèi)起催化作用 D、都有立體異構(gòu)專一性 15、酶的活性ZX是指 A、酶分子上含有必需基團(tuán)的肽段 B、酶分子與底物結(jié)合部位 C、酶分子與輔酶結(jié)合的部位 D、酶分子發(fā)揮催化作用的關(guān)鍵性結(jié)構(gòu)區(qū) 二、填空題 1．酶催化的機(jī)理是降低反應(yīng)的 ，不改變反應(yīng)的____________。 2．酶的特異性包括__________特異性，____________特異性與立體異構(gòu)特異性。 3．酶活性ZX內(nèi)的必需基團(tuán)分為__________和__________。 三、名詞解釋 1、米氏常數(shù) 2、同功酶 3、酶原 4、酶活性ZX 四、問答題 1、簡(jiǎn)述酶作為生物催化劑下一般化學(xué)催化劑的共性及個(gè)性。 2、簡(jiǎn)述酶的競(jìng)爭(zhēng)性YZ作用的特點(diǎn)。 展開

2009-05-01 00:02:25 623 2

生物化學(xué)題目，什么是酶？

《大學(xué)生物化學(xué)》題目：什么是酶？你是如何理解的？（30分）我需要準(zhǔn)確答案，請(qǐng)認(rèn)真回答... 《大學(xué)生物化學(xué)》題目：什么是酶？你是如何理解的？（30分）我需要準(zhǔn)確答案，請(qǐng)認(rèn)真回答 展開

2012-06-22 05:30:08 553 4

生物化學(xué) 里面的CE是什么

　

2010-10-29 21:52:42 622 3

物理和生物化學(xué)：發(fā)光現(xiàn)象的計(jì)算

1.A chromophore solution is places in a 1 × 1 cm regular fluorescence cuvette. The absorbance of this solution， at 1 cm path length， is 0.80 at 450 nm and 0.30 at 530 nm. When the sample is excited at 450 nm and the fluorescence emission... 1.A chromophore solution is places in a 1 × 1 cm regular fluorescence cuvette. The absorbance of this solution， at 1 cm path length， is 0.80 at 450 nm and 0.30 at 530 nm. When the sample is excited at 450 nm and the fluorescence emission is measured at 530 nm (both were set at a very narrow 5 nm slit for spectral band width)， the observed fluorescence emission is 100 arbitrary unit. Calculate the theoretical fluorescence emission intensity (using the same arbitrary unit) after corrections for the inner filter effects on both excitation and emission. Show critical steps of calculation. 2. For a particular Donor:Acceptor pair， the spectral overlap integral “J” between the corrected donor fluorescence emission and the acceptor absorption is 1.58 x10-13 (cm3 M-1) and the efficiency of fluorescence energy transfer is 0.667. Assuming 2/3 for the dipole orientation factor κ2 and 1.4 for therefractive index “n” of the medium， calculate the value of R. Show critical steps of calculation. 展開

2018-11-12 17:35:27 415 0

三種胺類物質(zhì)的生理功能 生物化學(xué)

三種胺類物質(zhì)的生理功能 生物化學(xué)

2016-11-15 17:01:13 624 1

生物化學(xué) 五肽的氨基酸序列分析

生物化學(xué) 五肽的氨基酸序列分析有一個(gè)五肽，其組成分析為Asp，Met，Lys，Ser，Leu。經(jīng)羧肽酶水解后首先得Leu，再經(jīng)DNFB處理得DNP-Asp。用胰蛋白酶水解得到一個(gè)二肽和一個(gè)三肽，其中已知二胎的N端為Asp和Met。試推出五肽AA'順序。

2018-11-25 14:06:27 618 0