Blood hemoglobin crystallization

Our blood contains the complex protein hemoglobin, which carries oxygen from the lungs to other parts of the body. In the genetic disease known as sickle-cell anemia, hemoglobin molecules are abnormal and have a lower solubility, especially in their unoxygenated form. Consequently, as much as 85% of the hemoglobin in red blood cells crystallizes out of solution. 

When HbS is deoxygenated it tends to "crystallize" in red blood cells, which contain 33% by weight hemoglobin. The crystallization (actually gel formation) distorts the cells into a sickle shape and these distorted corpuscles are easily destroyed, leading to anemia. The introduction of the hydrophobic valine residue in Hb S at position 6 near the end of the molecule helps form a new bonding domain by which the hemoglobin tetramers associate to form long semicrystalline microfilamentous arrays. 3 6 s... 

Much of this handbook is concerned with the how and why of crystallization and crystallizer design. This chapter will focus on the crystallization of one particular class of chemical compounds, namely the proteins. In the timeline of crystallization, protein crystallization is a newcomer. The first mention of protein crystal formation, roughly 150 years ago, involved crystallizing hemoglobin from the blood of various species (Lehman 1853 Reichert and Brown 1909 Debru 1983 McPherson 1991). This work was followed by the crystallization of a variety of proteins from plants to egg white (Sumner 1926). These early studies were pivotal in establishing that enzymes are proteins (Dounce and Allen 1988). The use of protein crystallization in purification and classification of biological chemicals resulted in the Nobel Prize for Chemistry being awarded to Sumner, Nothrop, and Stanley in 1946. 

G. Renal failure. Examples of dmgs and toxins causing renal failure are listed in Table I-28. Renal failure may be caused by a direct nephrotoxic action of the poison or acute massive tubular precipitation of myoglobin (rhabdomyolysis), hemoglobin (hemolysis), or calcium oxalate crystals (ethylene glycol) or it may be secondary to shock caused by blood or fluid loss or cardiovascular collapse. 

Contamination Exogenous feeal, food, bacteria, environmental, for example, chemical environmental cleaning agents (e.g., Clidox) Blood (cystocentesis) and lower urinary tract cells (catheterization) introduced by collection method Intrinsic sample differences crystals, casts, epithelial, and blood cells physicochemical properties (pH, albumin, hemoglobin) Collection procedure Addition or dilution of biomarkers biomarker stability assay interference... 

Fig. 5. At the left, molecules of normal hemoglobin or of oxygenated sickle-cell-anemia hemoglobin are shown, with random orientations, and at about the average distance apart characteristic of red-cell contents. At the right long strings of molecules of deoxygenated sickle-cell-anemia hemoglobin are shown, assuming the parallel orientation characteristic of the nematic liquid crystals that presumably form within the red cells in the venous blood of patients with sickle-cell anemia, and twist the red cells into the abnormal shape characteristic of the disease.

TeMmann s crystals, Morhemln crystals rhombic crystals formed by heating hemoglobin with sodium chloride and glacial acetic acid. T.c. are used for the microscopic detection of blood. 

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