Enzymatic properties

The number of different proteins in a membrane varies from less than a dozen in the sarcoplasmic reticulum to over 100 in the plasma membrane. Most membrane proteins can be separated from one another using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), a technique that has revolutionized their study. In the absence of SDS, few membrane proteins would remain soluble during electrophoresis. Proteins are the major functional molecules of membranes and consist of enzymes, pumps and channels, structural components, antigens (eg, for histocompatibility), and receptors for various molecules. Because every membrane possesses a different complement of proteins, there is no such thing as a typical membrane structure. The enzymatic properties of several different membranes are shown in Table 41-2. 

O. Noren. Studies on a soluble dipeptidase from pig intestinal mucosa. Enzymatic properties. Acta Chem Scand B28 711-716, 1974. 

Petrounia, I.P. and Arnold, F.H. (2000) Designed evolution of enzymatic properties. Current Opinion in Biotechnology, 11, 325-330. 

M., Ito, Y., Sugiura, M., Comparative study of human intestinal and hepatic esterases as related to enzymatic properties and hydrolyzing activity for ester-type drugs, Jpn. J. Pharmacol. 

The toxin component of the conjugate must be able to elicit cytotoxicity by ribosomal damage as it could in its native state. This means that the cell penetration and enzymatic properties of the toxin remain unaltered, although an antibody molecule is conjugated to it. 

In this chapter we describe the use of pea seeds to express the bacterial enzyme a-amylase. Bacterial exoenzymes like the heat stable a-amylase from Bacillus licheni-formis are important for starch hydrolysis in the food industry. The enzymatic properties of a-amylase are well understood [13,14], it is one of the most thermostable enzymes in nature and it is the most commonly used enzyme in biotechnological processes. Although fermentation in bacteria allows highly efficient enzyme production, plant-based synthesis allows in situ enzymatic activity to degrade endogenous reserve starch, as shown in experiments with non-crop plants performed under greenhouse conditions [12,15]. Finally, the quantitative and sensitive detection of a-amylase activ-... 

It is often difficult to distinguish a mutation, which causes a completely inactive protein to be produced instead of an enzyme, from an effective deletion of the gene, when neither protein nor enzyme is produced. If, however, a mutation causes a protein with weak enzymatic properties to be produced, the abnormal homozygote will be able to carry out the reaction, though at a lower rate than the normal the product of such a mutation is termed a leaky gene. ... 

Best, J. B. (1955). The inference of intracellular enzymatic properties from kinetic data obtained on living cells, J. Cell Comp. Physiol., 46, 1-27. 

Bach AW, Lan NC, Johnson DL, et al. cDNA cloning of human liver monoamine oxidase A and B molecular basis of differences in enzymatic properties. Proc Natl Acad Sci USA 1988 85(13) 4934—4938. 

Several enzymatic properties of nucleolin support a role for this protein in DNA repair and recombination it is able to bend DNA (Hanakahi and Maizels, 2000) and can either unwind double-stranded DNA or enhance annealing of complementary DNA strands (Hanakahi and Maizels, 2000 Nasirudin etai, 2005 Sapp et al, 1986 Tuteja et al, 1995). 

Pikuleva lA, Bjorkhem 1, Waterman MR. 1997. Expression, purification, and enzymatic properties of recombinant human cytochrome P450c27 CYP27). Arch Biochem Bio-phys 343 123-130. 

As described in the previous section, this strain produced significant amounts of three extracellular P-mannanases and a cell-associated P-mannosidase. The three P-mannanases differed in several enzymatic properties including optimum pH for enzyme action, optimum temperature, pH stability, thermal stability, isoelectric point and molecular weight. To elucidate the genetic basis for production of multiple forms,... 

I.P. Petrounia and RH. Arnold Designed Evolution of Enzymatic Properties. Curr. Opin. Biotechnol. 11, 325 (2000). 

Note 1 In many cases, especially for synthetic polymers, a molecule can be regarded as having a high relative molecular mass if the addition or removal of one or a few of the units has a negligible effect on the molecular properties. This statement fails in the case of certain properties of macromolecules which may be critically dependent on fine details of the molecular structure, e.g., the enzymatic properties of polypeptides. 

Suzuki T, Seko A, Kitajima K, Inoue Y, Inoue S (1994) Purification and enzymatic properties of peptide N-glycanase from C3H mouse-derived L-929 fibroblast cells Possible widespread occurrence of post-translational remodification of proteins by N-deglycosylation. J Biol Chem 269 17611-17618 Swaminathan S, Amerik AY, Hochstrasser M (1999) The Doa4 deubiquitinating enzyme is required for ubiquitin homeostasis in yeast. Mol Biol Cell 10 2583-2594 Tanaka K, Yoshimura T, Tamura T, Fujiwara T, Kumatori A, Ichihara A (1990) Possible mechanism of nuclear translocation of proteasomes. FEBS Lett 271 41-46... 

G. Legler, Action mechanism of glucosidase-splitting enzymes. II. Isolation and enzymatic properties of two 3-glucosidases from Aspergillus wentii, Hoppe Seyler s Zeitschr. Physiol. Chem., 348 (1967) 1359-1366. 

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