相关实验视频
Updated: Jul 17, 2025

09:43
Measurement of Heme Synthesis Levels in Mammalian Cells
Published on: July 9, 2015
12.1K
血口袋结构及其在祖先的环球蛋白中的功能影响
Yu Iritani1, Haruto Ishikawa1, Misao Mizuno1
1Department of Chemistry, Graduate School of Science, Osaka University, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
Biochemistry
|August 30, 2023
概括
研究人员重建了一种祖先蛋白,AncMH,是血红蛋白和髓红蛋白的共同祖先. AncMH将氧与其血基团结合,揭示了蛋白质稳定性和功能的进化.
科学领域:
- 生物化学 生物化学
- 进化生物学 进化生物学
- 结构生物学 结构生物学
背景情况:
- 蛋白质进化以提高稳定性,功能性和新功能.
- 对现存和祖先蛋白质的比较分析揭示了推动蛋白质进化的因素.
- 祖先序列重建是推断古代蛋白质序列的关键方法.
研究的目的:
- 描述AncMH的结构和功能,这是重建的血红蛋白和髓红蛋白的最后共同祖先.
- 为了理解血红蛋白结合蛋白的进化轨迹.
主要方法:
- 祖先序列重建以产生AncMH.
- 结构和功能测试以表征AncMH的血红素结合和氧气相互作用.
- 对AncMH的血口袋与现存的血红蛋白和髓红蛋白进行比较分析.
主要成果:
- AncMH成功地将氧气与它的血红组结合在一起.
- 在AncMH中,铁表现出五度协调,类似于人类成年血红蛋白和马类肌红蛋白.
- AncMH的血红素口袋结构更像是血红蛋白,而不是肌红蛋白.
- 与血红蛋白和髓红蛋白相比,AncMH显示出更快的自氧化率.
结论:
- 血红蛋白和髓红蛋白的进化是逐步发生的.
- 关键的进化过渡包括从六合到五合协调的转变,以及随后氧结合形式的稳定.
相关概念视频
Globular Proteins
7.5K
In organisms, proteins are the most abundant macromolecules. They act as the building blocks of life and play various crucial roles in the body. Proteins can be broadly classified into two distinct subtypes based on their shape and solubilities: globular proteins and fibrous proteins.
Globular proteins serve many important physiological functions, such as acting as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be soluble in the aqueous...
Globular proteins serve many important physiological functions, such as acting as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be soluble in the aqueous...
7.5K
Gene Families
8.9K
Gene families consist of groups of genes proposed to have originated from a common ancestor. Typically these arise through events in which a gene or genes are mistakenly duplicated during cell division. Unlike their parent genes (which are subject to selection pressure to maintain function), these gene copies do not need to preserve their sequences and may evolve at a relatively faster rate.
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
Occasionally these regions can be adapted to take on new roles within the organism, becoming novel genes...
8.9K
Globular and Fibrous Proteins
43.8K
Many proteins can be classified into two distinct subtypes - globular or fibrous. These two types differ in their shapes and solubilities.
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
43.8K
Protein Families
15.4K
Protein families are groups of homologous proteins; that is, they have similarities in amino acid sequences and three-dimensional structures. Protein families usually occur because of gene duplication, where an additional copy of a gene is inserted into the genome of an organism. Mutations that change the amino acids but still allow the protein to be properly synthesized, will lead to new protein family members. If these new proteins contain similar amino acids in key...
15.4K
Hemoglobin
3.7K
Hemoglobin is a globular protein made up of four subunits. Two of these subunits are alpha chains, and the other two are beta chains. Each subunit contains a molecule of heme, which has an iron atom and can bind to oxygen. When an oxygen molecule binds to one heme group, it changes the shape of hemoglobin, making it easier for the other heme groups to bind oxygen as well.
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
When all four heme groups are bound to oxygen, the resulting molecule is called oxyhemoglobin. As a result, arterial blood...
3.7K
Protein and Protein Structure
79.7K
Proteins are one of the most abundant organic molecules in living systems and have the most diverse range of functions of all macromolecules. Proteins may be structural, regulatory, contractile, or protective. They may serve in transport, storage, or membranes; or they may be toxins or enzymes. Their structures, like their functions, vary greatly. They are all, however, amino acid polymers arranged in a linear sequence.
A protein's shape is critical to its function. For example, an enzyme...
A protein's shape is critical to its function. For example, an enzyme...
79.7K

