Applications of alkaline protease fromConidiobolus in animal cell culture

Summary Alkaline protease fromConidiobolus has been tested as a substitute for trypsin in animal cell culture. Applications in the dissociation of cells for primary cell cultures, maintenance of cell lines and the production of G-bands on metaphase chromosomes are described. The advantages of a microbial enzyme for such applications are discussed.     

Lipase catalysed esterification of isosorbide and sorbitol

Summary Supported lipozyme catalysed esterification of isosorbide and sorbitol individually with oleic acid is studied in a tubular recycle reactor which is packed with enzyme, silica gel and solid reactant. Isosorbide produces only monooleate while sorbitol produces both mono and dioleates during the reaction.     

Sugar residues on proteins

Glycoproteins have become increasingly important in the structure and function of many different mammalian systems; for example, membrane glycoproteins and glycoprotein hormones. It is, therefore, important to understand their chemistry, which would include an understanding of both the carbohydrate and protein parts of the molecule. Since the chemical characterization of the protein moiety has been extensively examined and the techniques for its characterization are well worked out, only the carbohydrate portion of glycoproteins will be reviewed in this article. The chemical nature of the carbohydrate moiety of glycoproteins will be examined. First, the types of monosaccharides present in animal systems, especially those in the mammalian systems, will be described. Next, various types of simple and complex carbohydrate chains will be discussed to establish the diversity, size, and number of chains present in the carbohydrate units in different glycoproteins. Then, the type of linkages of the carbohydrate to the protein will be examined to determine if the primary sequence of protein is important in determining the size and type of carbohydrate chains present in glycoproteins. Finally, the current methods of structural elucidation such as monosaccharide sequence, intersugar bonds, and anomeric linkages in the carbohydrate moiety of glycoproteins will be reviewed. These methods include the techniques of periodate oxidation, methylation, partial acid hydrolysis, and specific glycosidase digestion of glycoproteins, as well as the latest techniques using micromethods of carbohydrate quantitation and characterization involving gas chromatography and mass spectrometry. The function of the carbohydrate in glycoproteins will also be considered. First, hormone glycoproteins will be discussed in their relationship to the immunological and biological function of the glycoprotein when the carbohydrate is sequentially removed. Next, the function of the carbohydrate in the turnover of glycoproteins will be discussed. These topics will be considered in order to develop an understanding of a specific function(s) of the carbohydrate in glycoproteins.     

Lipase catalysed transesterification of castor oil

Summary Lipase catalysed transesterification of castor oil with n-butanol gives mono and diglycerides, and butyl esters. n-Butanol is found to inhibit this reaction. Its amount influences the reaction rate and product distribution. Increasing the enzyme quantity increases the reaction rate and alters the product distribution.     

SARS-CoV-2 variant B.1.1.7 is susceptible to neutralizing antibodies elicited by ancestral spike vaccines

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Mode of action of lipoic acid in diabetes

Metabolic aberrations in diabetes such as hyperglycemia, ketonemia, ketonuria, reduced glycogen in tissues and reduced rates of fatty acid synthesis in the liver are corrected by the administration of lipoic acid. Dithiol octanoic acid is formed from lipoic acid by reduction and substitutes for Coenzyme A in several enzymatic reactions such as pyruvate dehydrogenase, citrate synthase, acetyl Coenzyme A carboxylase, fatty acid synthetase, and triglyceride and phospholipid biosynthesis; but not in the oxidation of fatty acids because of the slow rates of thiolysis of β-keto acyl dithioloctanoic acid. The overall effect of these changes in the key enzymic activities is seen in the increased rates of oxidation of glucose and a reduction in fatty acid oxidation in diabetes following lipoic acid administration.