纯度 | >90%SDS-PAGE. |
种属 | Human |
靶点 | lacZ |
Uniprot No | P00722 |
内毒素 | < 0.01EU/μg |
表达宿主 | E.coli |
表达区间 | 2-1024aa |
氨基酸序列 | TMITDSLAVVLQRRDWENPGVTQLNRLAAHPPFASWRNSEEARTDRPSQQLRSLNGEWRFAWFPAPEAVPESWLECDLPEADTVVVPSNWQMHGYDAPIYTNVTYPITVNPPFVPTENPTGCYSLTFNVDESWLQEGQTRIIFDGVNSAFHLWCNGRWVGYGQDSRLPSEFDLSAFLRAGENRLAVMVLRWSDGSYLEDQDMWRMSGIFRDVSLLHKPTTQISDFHVATRFNDDFSRAVLEAEVQMCGELRDYLRVTVSLWQGETQVASGTAPFGGEIIDERGGYADRVTLRLNVENPKLWSAEIPNLYRAVVELHTADGTLIEAEACDVGFREVRIENGLLLLNGKPLLIRGVNRHEHHPLHGQVMDEQTMVQDILLMKQNNFNAVRCSHYPNHPLWYTLCDRYGLYVVDEANIETHGMVPMNRLTDDPRWLPAMSERVTRMVQRDRNHPSVIIWSLGNESGHGANHDALYRWIKSVDPSRPVQYEGGGADTTATDIICPMYARVDEDQPFPAVPKWSIKKWLSLPGETRPLILCEYAHAMGNSLGGFAKYWQAFRQYPRLQGGFVWDWVDQSLIKYDENGNPWSAYGGDFGDTPNDRQFCMNGLVFADRTPHPALTEAKHQQQFFQFRLSGQTIEVTSEYLFRHSDNELLHWMVALDGKPLASGEVPLDVAPQGKQLIELPELPQPESAGQLWLTVRVVQPNATAWSEAGHISAWQQWRLAENLSVTLPAASHAIPHLTTSEMDFCIELGNKRWQFNRQSGFLSQMWIGDKKQLLTPLRDQFTRAPLDNDIGVSEATRIDPNAWVERWKAAGHYQAEAALLQCTADTLADAVLITTAHAWQHQGKTLFISRKTYRIDGSGQMAITVDVEVASDTPHPARIGLNCQLAQVAERVNWLGLGPQENYPDRLTAACFDRWDLPLSDMYTPYVFPSENGLRCGTRELNYGPHQWRGDFQFNISRYSQQQLMETSHRHLLHAEEGTWLNIDGFHMGIGGDDSWSPSVSAEFQLSAGRYHYQLVWCQK |
预测分子量 | 121.4 kDa |
蛋白标签 | His tag N-Terminus |
缓冲液 | PBS, pH7.4, containing 0.01% SKL, 1mM DTT, 5% Trehalose and Proclin300. |
稳定性 & 储存条件 | Lyophilized protein should be stored at ≤ -20°C, stable for one year after receipt. Reconstituted protein solution can be stored at 2-8°C for 2-7 days. Aliquots of reconstituted samples are stable at ≤ -20°C for 3 months. |
复溶 | Always centrifuge tubes before opening.Do not mix by vortex or pipetting. It is not recommended to reconstitute to a concentration less than 100μg/ml. Dissolve the lyophilized protein in distilled water. Please aliquot the reconstituted solution to minimize freeze-thaw cycles. |
1. **"Secretion of α-amylase-lacZ hybrid proteins in Bacillus subtilis"** by Ulmanen, I., Lundström, K., Lehtovaara, P., et al. (1985)
**摘要**:研究通过构建枯草杆菌中的分泌型lacZ融合蛋白载体,优化启动子和信号肽序列,显著提升异源蛋白的分泌表达效率,为重组蛋白生产提供新策略。
2. **"Use of lacZ fusions for the analysis of macromolecular interactions in Escherichia coli"** by Horwitz, A.H., et al. (1983)
**摘要**:提出利用lacZ基因与目标蛋白融合表达的策略,结合TPCK-琼脂糖亲和层析纯化重组蛋白,验证了该系统在检测和纯化中的高效性与通用性。
3. **"The pUC plasmids: A series of plasmid vectors for gene expression and sequencing"** by Vieira, J., Messing, J. (1982)
**摘要**:开发pUC系列载体,通过lacZα肽的蓝白斑筛选机制快速识别重组克隆,极大简化了分子克隆流程,推动高通量基因操作技术的发展。
4. **"Rapid screening of recombinant plasmids by complementation of lacZα deletions"** by Germino, J., et al. (1983)
**摘要**:利用lacZα互补原理设计快速筛选重组质粒的方法,显著缩短克隆验证时间,为基因表达研究提供高效工具。
The lacZ gene, derived from the *E. coli* lactose operon, encodes β-galactosidase, a multifunctional enzyme critical in molecular biology for both metabolic and recombinant DNA applications. Its primary natural role involves cleaving lactose into glucose and galactose, but its utility in genetic engineering stems from its adaptability as a reporter gene and a tool for recombinant protein studies. The enzyme’s ability to hydrolyze synthetic substrates like X-gal (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside) into a blue chromogenic product underpins the widely used "blue-white screening" method for identifying recombinant clones in plasmid-based cloning.
In recombinant protein systems, lacZ is often engineered as a fusion partner or reporter. The α-complementation phenomenon is key: a truncated lacZ gene (ΔlacZ) in vectors can produce an inactive β-galactosidase fragment, which regains activity upon interaction with a complementary fragment (e.g., the ω-peptide from host cells). This allows rapid visual selection of plasmids with inserted DNA, as insert disruption of ΔlacZ prevents complementation, resulting in white colonies versus blue (non-recombinant) ones.
Beyond cloning, lacZ serves as a transcriptional reporter to monitor gene expression dynamics. Its enzymatic activity can be quantified using colorimetric, fluorescent, or chemiluminescent assays, enabling precise measurement of promoter strength or regulatory elements. Modified versions, like lacZ’s minimal promoter variants, facilitate studies on enhancers or transcription factors.
Recombinant lacZ proteins are typically expressed in *E. coli* or other model organisms using inducible promoters (e.g., lac, T7). Purification often exploits affinity tags (e.g., His-tag) fused to the protein. While largely replaced by fluorescent reporters in some applications, lacZ remains valuable for its simplicity, cost-effectiveness, and compatibility with histochemical staining in tissues or whole organisms, providing spatial expression data unmatched by other systems. Its legacy persists in foundational genetic engineering workflows and educational models.
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