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Title Chemical keys to an understanding of life processes
Subject Biochemistry ; Nucleic acids; Proteins
Description Twenty Second Annual Frederick William Reynolds Lecture.
Creator Smith, Emil L., 1911-
Publisher Extension Division, University of Utah
Date 1958-01-13
Date Digital 2008-05-29
Type Text
Format image/jpeg
Digitization Specifications Original scanned on Epson Expression 10000XL flatbed scanner and saved as 400 ppi uncompressed tiff. Display images generated in PhotoshopCS and uploaded into CONTENTdm Aquisition Station.
Resource Identifier,564
Source LD5526.U8 n.s. v.49 no.11
Language eng
Relation Digital reproduction of "Chemical keys to an understanding of life processes," J. Willard Marriott Library Special Collections
Rights Digital Image Copyright University of Utah
Metadata Cataloger Seungkeol Choe; Ken Rockwell
ARK ark:/87278/s6c8277g
Setname uu_fwrl
Date Created 2008-07-29
Date Modified 2008-07-31
ID 319868
Reference URL

Page Metadata

Title Page13
Description CHEMICAL KEYS TO AN UNDERSTANDING OF LIFE PROCESSES 13 The schematic diagram of insulin structure is shown in Figure 1. The letters represent abbreviations for each of the amino acid residues present in insulin. We need not be concerned here with the details, but we should note that some amino acids may occur only once, others may occur at different positions more than once. What is important is that in a given species of insulin, in this case the one from the cow, the arrangement of the amino acids and hence of the constituent atoms is as definite as in the case of a molecule of water or sucrose. Insulins of other species differ from bovine insulin insofar as a few of the amino acid residues have been replaced by others but the main structure is the same. Thus species differences are reflected in the structure of individual proteins. All mammalian insulins are much alike and have the same functional activity in mammals. It is certainly fortunate that this is so, because bovine and porcine insulins are used therapeutically in the treatment of human diabetes. When there are large differences among individual proteins from different species, we cannot with impunity transfer such proteins from one species into another. As you all know, blood transfusion into humans is restricted to use of human blood and indeed to blood of a particular type. However, if the cellular elements are removed from the blood, the remaining human plasma can be used for transfusion without typing, but we still cannot use the plasma of other species. Thus there is a considerable degree of what is called species specificity and this is due to the fact that the proteins of a given species have a distinctive structure. Other examples of this will be mentioned later. To return to the problem of the proteins which possess catalytic activity, each enzyme is specific in its catalytic function and hence must be specific in its structure. As yet, we do not know the complete structure for any enzyme, but it will be only a relatively short time before we do, since a number of laboratories, including our own, are actively at work in this field. One enzyme whose structure has been almost completely elucidated is ribonuclease (Fig. 2). Its particular function is of no immediate concern. What is significant is that the arrangement of the constituent amino acids is very precise and that the structure differs greatly from that of insulin, or indeed, from any other protein which has been studied. What is it about the amino acid sequence and the structure of the protein that determines its enzymic specificity and activity ? We
Format image/jpeg
Identifier 018-RNLT-SmithE_Page13.jpg
Source Original Manuscript: Chemical keys to an understanding of life processes by Emil L. Smith.
Setname uu_fwrl
Date Created 2008-07-29
Date Modified 2008-07-29
ID 319854
Reference URL