Alkalimonas amylolytica N10是中科院微生物所馬延和研究員課題組篩選自內(nèi)蒙古鹽堿湖中的一株嗜堿菌新種,，為革蘭氏陰性菌,。該菌能夠在pH8.0-11.0的堿性環(huán)境中生存，其最適生長的環(huán)境pH約為9.5,。目前對于嗜堿菌的嗜堿機理尚不完全清楚,，研究領域也主要集中在革蘭氏陽性嗜堿菌的某個或某一類蛋白,，而未考慮生物體可能是通過一種蛋白協(xié)同網(wǎng)絡效應的方式來進行的,。
該研究通過對嗜堿菌N10在不同pH環(huán)境中生長時的膜蛋白質(zhì)組和胞漿蛋白質(zhì)組對環(huán)境的應答情況進行了系統(tǒng)的研究，結果表明能量代謝相關蛋白,、質(zhì)子轉(zhuǎn)運蛋白等在不同堿性的環(huán)境中發(fā)生了顯著的差異變化,，這可能與嗜堿菌N10的嗜堿機制相關。該研究成果發(fā)表在《蛋白質(zhì)組學》（Proteomics）第九卷上，為從全局角度闡釋嗜堿菌的嗜堿機理提供了重要參考,。（生物谷Bioon.com）
生物谷推薦原始出處：
Proteomics,，doi:10.1002/pmic.200800244 ，Quanhui Wang ,，Yanhe Ma
Exploring membrane and cytoplasm proteomic responses of Alkalimonas amylolytica N10 to different external pHs with combination strategy of de novo peptide sequencing
Quanhui Wang 1, Huiming Han 1, Yanfen Xue 1, Zhong Qian 2 3, Bo Meng 2 3, Fuli Peng 2 3, Zhuowei Wang 2 3, Wei Tong 2 3, Chuanqi Zhou 2 3, Qian Wang 2 3, Yonghao Guo 1, Gang Li 1, Siqi Liu, Dr. 2 3, Yanhe Ma, Dr. 1 *
1State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, P. R. China
2Center of Proteomic Analysis, Beijing Genomics Institute, Chinese Academy of Sciences, Beijing, P. R. China
3Beijing Proteomics Institute, Shunyi, Beijing, P. R. China
*Correspondence to Yanhe Ma, State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, P. R. China
ABSTRACT
Identification of differentially proteomic responses to external pHs would pave an access for understanding of survival mechanisms of bacteria living at extreme pH environment. We cultured Alkalimonas amylolytica N10 (N10), a novel alkaliphilic bacterium found in Lake Chahannor, in media with three different pHs and extracted the correspondent membrane and cytoplasm proteins for proteomic analysis through 2-DE. The differential 2-DE spots corresponding to the altered pHs were delivered to MALDI TOF/TOF MS for protein identification. Since the genomic data of strain N10 was unavailable, we encountered a problem at low rate of protein identification with 18.1%. We employed, therefore, a combined strategy of de novo sequencing to analyze MS/MS signals generated from MALDI TOF/TOF MS. A significantly improved rate of protein identification was thus achieved at over than 70.0%. Furthermore, we extensively investigated the expression of these pH-dependent N10 genes using Western blot and real-time PCR. The conclusions drawn from immunoblot and mRNA measurements were mostly in agreement with the proteomic observations. We conducted the bioinformatic analysis to all the pH-dependent N10 proteins and found that some membrane proteins participated in iron transport were differentially expressed as external pH elevated and most of differential proteins with increased or bell-shape mode of pH-dependence were involved in bioenergetic process and metabolism of carbohydrates, fatty acid, amino acids, and nucleotides. Our data thus provide a functional profile of the pH-responsive proteins in alkaliphiles, leading to elucidation of alkaliphilic-adaptive mechanism.
