Hormones, purification

Immunoaffinity chromatography can provide extensive purification of endogenous hormones in plant extracts [60] (see Figs. 6 and 7 in Section 6.2). Both monoclonal and polyclonal antibodies have been used to produce immunoaffinity supports for lAA [60,61], GAs [62,63] and cytokinins [64,65]. Despite the enormous potential of the procedure, it has as yet not found widespread application in plant hormone purification protocols. The situation is unlikely to change until a range of immunoaffinity supports are available from commercial sources at affordable prices. The raising of antibodies against plant hormones, the preparation of a variety of immunoaffinity supports and their application in plant hormone analysis are discussed and evaluated in Chapter 3. 

HUMN FOLLICLE-STIMULATING HORMONE. PURIFICATION AND SOME BIOLOGICAL PROPERTIES... 

Human growth hormone was originally manufactured by isolation of the natural product from human pituitaries and subsequent purification of the protein. Since 1985, manufacture of hGH has been almost exclusively by recombinant DNA technology. 

Retinyl acetate [127-47-9] M 328.5, m 57". Separated from retinol by column chromatography, then crystd from MeOH. See Kofler and Rubin [Vitamins and Hormones (NY) 18 315 1960] for review of purification methods. Stored in the dark, under N2 or Ar, at 0°. See Vitamin A acetate p. 574 in Chapter 6. 

Fermentation broths are complex, aqueous mixtures of cells, comprising soluble extracellular, intracellular products and any unconverted substrate or unconvertible components. Recovery and extraction of product is important in bioprocess engineering. In particular separation is a useful technique it depends on product, its solubility, size of the process, and product value. Purification of high-value pharmaceutical products using chromatography such as hormones, antibody and enzymes is expensive and difficult to scale up.1 Tire necessary steps to follow a specific process depend on the nature of the product and the characteristics of the fermentation broth. There are a few steps for product recovery the following processes are discussed, which are considered as an alternative for product recovery from fermentation broth. 

Proteins such as antibodies, enzymes, hormones and vaccine antigens can be used to prevent, diagnose and treat a range of diseases. Such molecules are therefore of paramount importance in health and medicine. Historically, many of these proteins have been isolated from human or animal sources. However, the low quantities present in such source material coupled with safety risks and high purification costs have limited the availability of protein therapeutics and vaccines for many types of disease. 

EPO is present in serum and (at very low concentrations) in urine, particularly of anaemic individuals. This cytokine/hormone was first purified in 1971 from the plasma of anaemic sheep, and small quantities of human EPO were later purified (in 1977) from over 2500 1 of urine collected from anaemic patients. Large-scale purification from native sources was thus impractical. The isolation (in 1985) of the human EPO gene from a genomic DNA library facilitated its transfection into CHO cells. This now facilitates large-scale commercial production of the recombinant human product (rhEPO), which has found widespread medical application. 

Proteins are frequently powerful immunogens and the availability of specific antibodies, particularly monoclonal antibodies, makes the technique of affinity chromatography very useful in the separation and purification of individual proteins. The technique has been used to purify a wide range of proteins such as hormones, membrane receptors and complement proteins. However, it is not restricted to proteins and is potentially applicable to any immunogenic substance. The availability of suitable antibodies is essential and these may be raised by whole animal polyclonal techniques or by monoclonal cell culture. The former antibodies may need some prior purification before being immobilized. 

The Purification and Properties of Certain Protein Hormones Bacon F. Chow... 

Due to the strong and selective binding that characterizes many affinity ligands, solutes that are analyzed or purified with these ligands can often be separated with little or no interferences from other sample components. In many cases, the solute of interest can be isolated in only one or two steps, with purification yields of hundred- to several thousandfold being common [2,4-6]. In work with hormone receptors, purification yields approaching one millionfold have even been reported with affinity-based separations [5]. 

Nakajima, M. and Yamaguchi, I., Purification of plant hormones by immunoaffinity chromatography,... 

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