Effect of proteins on the reversibility of the thermal inactivation ofBacillus subtilis α-amylase

Zusammenfassung Die Reaktivierung von thermisch desaktivierter-Amylase ausBacillus subtilis durch Zusatz von Guanidin-HCl oder Harnstoff oder von Guanidin mit Zusatz verschiedener Proteine wurde untersucht.     

Fucosidases du suc digestif d'Helix pomatia

Summary The-d-fucosidase and -l-fucosidase activities of digestive juice ofHelix pomatia have been studied.-d-fucosidase can be separated from-d-galactosidase by heat inactivation.     

Deformation and rupture of the oceanic crust may control growth of Hawaiian volcanoes

Hawaiian volcanoes are formed by the eruption of large quantities of basaltic magma related to hot-spot activity below the Pacific Plate. Despite the apparent simplicity of the parent process--emission of magma onto the oceanic crust--the resulting edifices display some topographic complexity. Certain features, such as rift zones and large flank slides, are common to all Hawaiian volcanoes, indicating similarities in their genesis; however, the underlying mechanism controlling this process remains unknown. Here we use seismological investigations and finite-element mechanical modelling to show that the load exerted by large Hawaiian volcanoes can be sufficient to rupture the oceanic crust. This intense deformation, combined with the accelerated subsidence of the oceanic crust and the weakness of the volcanic edifice/oceanic crust interface, may control the surface morphology of Hawaiian volcanoes, especially the existence of their giant flank instabilities. Further studies are needed to determine whether such processes occur in other active intraplate volcanoes.     

Nouvelle méthode de préparation de la préalbumine sérique et principales caractéristiques physico-chimiques

Summary Prealbumin is prepared by a new method. Its homogeneity is demonstrated and its electrophoretic behaviour is discussed. Some new physico-chemical characteristics are determined.     

Amino acid incorporation by human milk fat globules membranes (author's transl)]

Human milk fat globule membranes (MFGM) can incorporate radioactive 14C amino acids in a hot trichloracetic acid-insoluble material. Aspecific adsorption and bacterial contamination are unlikely. The products of protein synthesis were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate or by action of proteolytic enzymes. Various inhibitors of protein synthesis were assayed. Fragments of rough endoplasmic reticulum or mitochondria could be involved in this incorporation.     

Action des enzymes sur la gonadotropine urinaire de ménopause

Summary The action of various proteolytic and glucidolytic enzymes on the biological potency of Human Menopausal Gonadotropin was studied. Trypsin, chymotrypsin, papaïn and glucosidase attack the gonadotropin only after 6 h of digestion. Carboxypeptidase and RDE produce a rapid inactivation.     

Incorporation d'acides aminés radioactifs dans les membranes des globules lipidiques du lait humain

Summary Human milk fat globule membranes (MFGM) can incorporate radioactive¹⁴C amino acids in a hot trichloracetic acid-insoluble material. Aspecific adsorption and bacterial contamination are unlikely. The products of protein synthesis were analyzed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate or by action of proteolytic enzymes. Various inhibitors of protein synthesis were assayed. Fragments of rough endoplasmic reticulum or mitochondria could be involved in this incorporation.