Urea PAGE

Table 2.8. Casting protocol for the acidic urea PAGE...

Urea, Pages 409-411, Midhun C. Korrapati and Harihara M. Mehendale SummaryPlus Full Text + Links PDF (60 K)... 

In this nomenclature, the "nonmuscle" LC17a is the more basic and the "gizzard type" smooth muscle LClTb is the more acidic isoform (Kelley et al., 1993), and therefore the LClTb of urea-PAGE corresponds to the LClTa of the 2D gel and the LClTa of the former corresponds to the LClTb of the latter. In this review, we shall refer to LClTa as the more acidic and LClTb as the more basic isoform, and will make the appropriate corrections in the data presentation of the reverse designations. 

Gel electrophoresis, especially alkaline (pH 9.0) urea-PAGE, is the best method for characterizing the large water-insoluble (WISF) peptides and is also useful for characterizing the larger water-soluble (WSF) peptides. Ledford et al. (1966) and Marcos et al. (1979) showed differences between the electrophoretograms of 7 and 34 cheese varieties, respectively, by urea-PAGE both studies involved only one sample, of unknown age, history, or quality, for each variety and hence may not have been typical. 

We have made several comparative studies on Cheddar cheese in relation to starter type, manufacturer, ripening temperature, age, and quality. In one such study, urea-PAGE of the WSF and WISF from 22 6-month-old cheeses made using single strain starters showed very little difference... 

The subunit composition determined by SDS/urea-PAGE is given in Table I. Immunoblot analysis identifies two subunits of 18.5 kDa and the 9.5 kDa subunit as the psaD. psaF and psaC gene products, coding for the ferredoxin-, the cytochrome c-and the FeSA/FeSe-binding protein, respectively (not shown 5). While the two big subunits may be attributed to the psaA and osaB gene product (5), the identity of the other four small subunits is unknown. 

Fig.l SDS-urea PAGE of intrinsic PSII membrane protein fractions. Separation was achieved by ACA 54 gel filtration chromatography. Staining was carried out with Coomassie R 250. 

Fig.2 SDS-urea PAGE of the purified 14 kDa protein. Approximately 2 fig were loaded onto the gel. Staining was carried out with silver.

Fig. 3 Immunological assay. Purified chi a/b proteins were separated by SDS-urea PAGE and transferred to nitrocellulose. The filter was assayed with polyclonal antibodies raised against purified CP26 and CP29.

Fig. 5 Analysis of the sucrose band 4- a)immunological analysis of the polypeptides b) polypeptide composition SDS-urea PAGE) of the green fractions F) 1 to 4 obtained from lEF in 1% DM.

Fig. 4A,B Acid-urea PAGE of P]-poly(ADP-ribosyl)ated histone HI isolated from histone Hl-DNA complexes. Histone Hl-DNA complexes (H1/DNA 1/1) were produced according to Hsiang and Cole [21] and were poly(ADP-ribosyl)ated by the purified calf thymus poly(ADP-ribose) polymerase (2 jug/OD unit) at 200 ijlM NAD and precipitated by 20% TCA (CI3 AcOH). Histone HI was extracted as described by Aubin et al. [8, 9] and was subjected to electrophoresis on 2.5 M urea - 0.9 N acetic acid vertical slab gels according to Panyim and Chalkley [17]. a 30 s pulse, b-d 5 min, 15 min, 30 min 200 tiMf NAD chase at 30°C, respectively. A Stained gel, B autoradiogram of the gel. The arrow indicates hyper(ADP-ribosyl)ated forms of histone HI. Histone HI and DNA have been isolated from calf thymus tissue...

Some enzymes have an obligatory requirement for a particular activator, i.e. they have no measurable activity if the activator is absent. In such cases, the activators effectively change the max of enzyme rather than the substrate dependence. An example of such an enzyme is carbamoyl phosphate synthetase which is involved in the conversion of ammonia to urea (page 283). This enzyme is completely inactive in the absence of N-acetylglutamate, which increases the activity at all substrate concentrations. 

Amobarbital is a sedative marketed under the trade name Amytal. Propose a synthesis of amobarbital, using diethyl malonate and urea (page 2) as two of the starting materials. 

Electrostatic interaction between chitosan and milk fat globule fragment facilitated fat and protein recovery. Fernandez and Fox (Fernandez, Fox, 1997) reported the use of chitosan to remove proteins and peptides from cheese whey. Urea-PAGE (polyacrylamide gel electroplorosis) showed that chitosan gave good fractionation of water-soluble extract at pH 2, 3, and 4. At pH 5, 6, and 7, most of the nitrogen of the water-soluble extract remained soluble in 0.02% chitosan. 

---