来自C3植物叶片的甘油酸激酶。

Glycerate kinase from leaves of C3 plants.

作者信息

Schmitt M R, Edwards G E

出版信息

Arch Biochem Biophys. 1983 Jul 1;224(1):332-41. doi: 10.1016/0003-9861(83)90217-5.

Abstract

D-Glycerate-3-kinase (EC 2.7.1.31) in six C3 species, including dicots (Pisum sativum, Spinacea oleracea, Antirrhinum majus) and monocots (Secale cereale, Hordeum vulgare, Avena sativa), ranged in activity from 44 to 353 mumol X mg chl-1 X h-1. Studies with protoplast extracts of these species indicate that the enzyme is localized in the chloroplasts. Glycerate kinase was partially purified from Secale (rye, 288-fold) and Pisum (pea, 252-fold) chloroplasts by DEAE-cellulose chromatography, sucrose gradient centrifugation, and chromatofocusing. The enzymes from both species showed similar physical (Mr = 41,000, pI = 4.6-4.7) and kinetic (Km ATP = 655 to 692 microM, Km D-glycerate = 180-188 microM) properties. Activity of the enzyme was essentially insensitive to variations in assay pH from 6.4 to 9.0 and to energy charge variations from 0.4 to 1.0. Rye glycerate kinase was able to utilize UTP and GTP but less effectively than ATP. Neither ADP nor pyrophosphate served as an energy source. Mn2+, Co2+, Ca2+, and Sr2+ could function as metal cofactors, although to a lesser extent than Mg2+. Millimolar levels of sulfate were found to significantly inhibit the enzyme while similar concentrations of other anions (Cl-, NO-3, NO-2, and acetate) had little or no effect.

摘要

六种C3植物中的D -甘油酸-3-激酶（EC 2.7.1.31），包括双子叶植物（豌豆、菠菜、金鱼草）和单子叶植物（黑麦、大麦、燕麦），其活性范围为44至353 μmol·mg叶绿素⁻¹·h⁻¹。对这些植物原生质体提取物的研究表明，该酶定位于叶绿体中。通过DEAE -纤维素色谱法、蔗糖梯度离心法和色谱聚焦法，从黑麦（288倍）和豌豆（252倍）叶绿体中对甘油酸激酶进行了部分纯化。这两种植物的酶表现出相似的物理性质（Mr = 41,000，pI = 4.6 - 4.7）和动力学性质（Km ATP = 655至692 μM，Km D -甘油酸 = 180 - 188 μM）。该酶的活性对测定pH值在6.4至9.0之间的变化以及能量电荷在0.4至1.0之间的变化基本不敏感。黑麦甘油酸激酶能够利用UTP和GTP，但效率低于ATP。ADP和焦磷酸均不能作为能量来源。Mn²⁺、Co²⁺、Ca²⁺和Sr²⁺可以作为金属辅因子发挥作用，尽管程度低于Mg²⁺。发现毫摩尔水平的硫酸盐会显著抑制该酶，而相似浓度的其他阴离子（Cl⁻、NO₃⁻、NO₂⁻和乙酸盐）几乎没有影响。