英国公共关系学论文代写:血红蛋白

18 5月 英国公共关系学论文代写:血红蛋白

英国公共关系学论文代写:血红蛋白

血红蛋白巴塞特是一种具有降低氧亲和力的Hb异常变异。它是在一个男孩(高加索人)身上发现的,他经历了发绀的发作。高效液相色谱法和阳离子交换和反相显示,孩子有突变的异常Hbα-globin(8),胰蛋白酶的消化异常α-globin肽与高效液相色谱分析显示异常α-T11肽洗脱。采用电喷雾质谱法和Edman测序的方法,通过x射线晶体学的x射线结晶学分析,发现了在94位置上的aspala替代。功能研究表明,Hb变异降低了氧亲和力,降低了玻尔效应,降低了亚单位合作。x射线结晶学结果描述了结构修饰对Hb变异体氧结合性质的可能影响。

英国公共关系学论文代写:血红蛋白
负责运输氧气的能力大多数脊椎动物的红细胞,野生型血红蛋白(HbA)蛋白在1840年首次被发现Hunefeld(9)。HbA的四级结构是四聚物组成的四个球状的子单元,两个α-chains和两个β-chains,包括141年和146年分别氨基酸残基(11)。亚基在两个接触区域(1 1和1 2 contacts)相连,被折叠成在形状和大小上相似的三级结构,但由不同的氨基酸序列组成。血红素组,每个亚基通过共价键包围,是由卟啉环的一个铁离子(价)中心(7)。负责氧气绑定,铁离子与卟啉环上的四个氮原子坐标平面上和共价结合到另一个氮原子从一个组氨酸残基在F8位置(名为近端组氨酸)从下面(6)。

英国公共关系学论文代写:血红蛋白

Hemoglobin Bassett is an abnormal Hb variant that has decreased oxygen affinity. It was discovered in a male child (Caucasian) who experienced the episodes of the cyanosis. The high performance liquid chromatography and Cation exchange and reversed phase showed that the child has the abnormal Hb with the mutation in α-globin (8). The Tryptic peptide digests of abnormal α-globin with HPLC analysis shows the abnormal elution of α-T11 peptide. The studies with electrospray mass spectrometry and Edman sequencing of the tryptic peptide α-T11 and structural analysis by the X-ray crystallography shows the Asp-Ala substitution at α94 position. The functional studies revealed that the Hb variant decreased oxygen affinity decreased Bohr Effect and reduced subunit cooperatives. The X-ray crystallography result describes the probable effect of structural modification on oxygen binding properties of the Hb variant.

英国公共关系学论文代写:血红蛋白
Responsible for oxygen transport ability of most vertebrates’ red blood cells, wild-type hemoglobin A (HbA) protein was first discovered in 1840 by Hünefeld (9). HbA’s quaternary structure is a tetramer composed of four globular subunits, which are two α-chains and two β-chains, involving 141 and 146 amino acids residues respectively (11). The subunits are connected in two contact regions (α1β1 and α1β2 contacts), and are folded into tertiary structures that are similar in terms of shape and size, but are composed of different amino acid sequences. The heme groups, enclosed by each subunit through covalent bonds, are composed of a porphyrin ring with an iron ion (Fe2+) in the center (7). Responsible for oxygen binding, the iron ion coordinates with four nitrogen atoms of the porphyrin ring in the plane and is covalently bound to another nitrogen atom from a histidine residue in F8 position (named proximal histidine) from below (6).