TERMIUM Plus^®

Record 1,  Textual support,  English

Record number: 1, Textual support number: 1 CONT

A homogeneous data structure is one that contains data elements of the same type...  2, record 1, English, - homogeneous%20data%20structure

Record 1,  Textual support,  French

Record 1,  Textual support,  Spanish

Record 2,  Textual support,  English

Record number: 2, Textual support number: 1 CONT

Today nearly 2, 000 different enzymes are known. Many have been isolated in pure homogeneous form, and at least 200 have been crystallized.... NMR studies of globular proteins in solution give data consistent with the crystal structure, as has been amply demonstrated for lysozyme. However, where there is an equilibrium among two or more conformations of the enzyme in solution, crystallization may select out only one of the conformations. [alpha]-Chymotrypsin has a substantial fraction of an inactive conformation present under the conditions of crystallization, but only the active form of the enzyme crystallizes. An allosteric effector molecule that changes the conformation of the protein in solution may have no effect on the crystalline protein, as has been found, for example, with phosphorylase b. The enzyme is frozen in one conformation, with the crystal lattice forces preventing any conformational change. On the other hand, the addition of an effector to phosphorylase a causes the crystals first to crack and then to anneal, giving crystals of the enzyme in a second conformation.  2, record 2, English, - crystallize

Record 2,  Textual support,  French

Record number: 2, Textual support number: 1 DEF

Amener une substance à l'état de cristaux, lui donner la contexture régulière des cristaux.  1, record 2, French, - cristalliser

Record number: 2, Textual support number: 1 CONT

Pour cristalliser une protéine, on place des échantillons en présence d'agents précipitants : solutions salines, solvants organiques ou polyéthylène glycol, dont on augmente progressivement la concentration par diffusion en phase gazeuse ou liquide. Pour les protéines membranaires, ces expériences se font en présence de détergents "doux". Comme la solubilité des protéines dépend du pH, de la température, de la présence d'ions métalliques ou de petites molécules qui se fixent sur la protéine, etc., des centaines de tests sont souvent nécessaires pour mettre au point une cristallisation.  2, record 2, French, - cristalliser

Record 2,  Textual support,  Spanish