Ultrastructural localization of the high molecular weight proteins associated with in vitro-assembled brain microtubules

Microtubules isolated from brain extracts by in vitro assembly (1, 19, 23) are composed principally of two tubulins and two high molecular weight proteins (microtubule-associated proteins [MAPS] 1 and 2) (2,5,7,20). Recently, it was demonstrated that in vitro-assembled brain microtubules (neurotubules) are coated with filaments (5, 7) which are similar to the filaments attached to neurotubules in situ (4, 15, 21, 24, 25), and it was suggested that the filaments are composed of the higher molecular weight MAPs (5, 7, 12). In this study, microtubules were assembled in the presence and absence of the MAPs, and thin sections of the microtubules were examined by electron microscopy. The results show that the filaments only occur on microtubules assembled in the presence of the MAPs and it is therefore concluded that the filaments are composed of the high molecular weight MAP's.     

Enterococcal surface protein Esp is not essential for cell adhesion and intestinal colonization of Enterococcus faecium in mice

Background  

Enterococcus faecium has globally emerged as a cause of hospital-acquired infections with high colonization rates in hospitalized patients. The enterococcal surface protein Esp, identified as a potential virulence factor, is specifically linked to nosocomial clonal lineages that are genetically distinct from indigenous E. faecium strains. To investigate whether Esp facilitates bacterial adherence and intestinal colonization of E. faecium, we used human colorectal adenocarcinoma cells (Caco-2 cells) and an experimental colonization model in mice.     

Biochemical changes in primary wheat leaves during growth and senescence

Changes in the different forms of the total activity of peroxidases (soluble, ionically and covalently bound), in the soluble isoperoxidase composition, and in the content of protein and chlorophyll during growth and senescence of the intact primary leaves of spring wheat were studied. The forms of peroxidases are in inverse relationship to the growth and increase during development and senescence, especially towards the end of senescence. The activity of peroxidases does not follow the physiological age of wheat leaves during the whole period of vegetation unlike the contents of protein and chlorophyll. The intensity of anodic and cathodic peroxidase isoenzyme bands 1 and 5 increases during senescence, but anodic bands number 2 and 4, cathodic bands 2 and 3 decrease. Changes in the activity of peroxidases and in the content of protein and chlorophyll as indicators of senescence are discussed.