Mammalian metabolism knowledge

Whilst there have been some reports of its presence in plants, lactose is largely a product of mammalian metabolism, being synthesized by the female and secreted in her milk. Since it can be so readily isolated in pure form from this source, a great deal of the fundamental knowledge about carbohydrates has been obtained from its study. Thus, the first research problem of C. S. Hudson was, at his own request, a physicochemical study of the mutarotation of milk sugar, a phenomenon that was not understood at that time. His first scientific paper, published in 1902, at the age of 21, was on the five forms of milk sugar. It is appropriate that, forty years later, the first chemical synthesis of lactose should also have been achieved by him. Lactose had been a recurring theme in his life, and we should like to dedicate this review to his memory. 

As the productivity of mammalian cell lines is lower compared with that of other production systems (bacteria, insect cells, etc.), it is desirable to improve the productivity per cell or the total cell yield per unit volume of culture. An increase in the specific productivity could involve enhancement at the genetic level by gene amplification or by the addition of an inducer to enhance the transcription of a gene. However, knowledge of mammalian cell metabolism helps in the development of strategies for productivity enhancement, as changes in the culture conditions can affect both metabolism and productivity. 

Goldenberg HA, Regulation of mammalian iron metabolism current state and need for further knowledge. CritRev Clin Lab Sci 34(6) 529-72, 1997. 

Vertebrate, especially mammalian, lipoproteins have been extensively studied. In the invertebrate world, only insect lipoproteins have received serious attention. Whereas vertebrates rely on a battery of lipoproteins (chylomicrons, very low-density lipoproteins, low-density lipoproteins, and high-density lipoproteins) to effect lipid transport, insects use primarily a single type of lipoprotein, lipophorin, for lipid transport. Lipophorin is both more versatile than vertebrate lipoproteins in terms of the diverse lipids it transports and more efficient than vertebrate lipoproteins in that, for the most part, it delivers lipids to tissues without being internalized and destroyed. We believe that new insights can be obtained from an understanding of insect lipoproteins, and in this article we review the current state of knowledge about the structure and metabolism of lipophorins. 

META [22,23] was developed by Gilles Klopman and coworkers. The mammalian model covers a wide range of reactions promoted by 26 types of enzymes. Metabolic products can be assessed automatically for potential carcinogenicity and the results reported to the user. Separate knowledge bases cover aerobic biodegradation, anaerobic biodegradation, and photodegradation. 

Attempts to calculate the site of metabolism based on molecular orbital theory have met with some success. Currently the state-of-the-art method is to calculate an electron density map of molecules using quantum mechanics and then calculate a steric factor using knowledge of the CYP active site.116 Taken together these two parameters have successfully predicted the sites of oxidation for limited sets of molecules.116 This approach may be dramatically enhanced as the crystal structures of more mammalian CYP enzymes become available.126-128... 

The answer can only be given in general terms from a knowledge of all of metabolism, such as is given in this book but since we emphasize mammalian biochemistry, is it not obvious that the relative abundance of enzyme types in mammals will be the same as in prokaryotes However, a precise answer is obtained from the EC book on enzyme nomenclature. 

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