Erythrocyte proteins

There is also inside-outside (transverse) asymmetry of the phospholipids. The choline-containing phospholipids (phosphatidylcholine and sphingomyelin) are located mainly in the outer molecular layer the aminophospholipids (phosphatidylserine and phos-phatidylethanolamine) are preferentially located in the inner leaflet. Obviously, if this asymmetry is to exist at all, there must be limited transverse mobility (flip-flop) of the membrane phospholipids. In fact, phospholipids in synthetic bilayers exhibit an extraordinarily slow rate of flip-flop the half-life of the asymmetry can be measured in several weeks. However, when certain membrane proteins such as the erythrocyte protein gly-cophorin are inserted artificially into synthetic bilayers, the frequency of phospholipid flip-flop may increase as much as 100-fold. 

Murray, Jr., E. D. and Clarke, S., Synthetic peptide substrates for the erythrocyte protein carboxyl methyltransferase, J. Biol. Chem., 259, 10722, 1984. 

Serum amyloids Coagulation factors Tumor necrosis factor Erythrocyte proteins Apolipoproteins... 

What is the function of the membrane skeleton There is a group of hereditary diseases including spherocytosis in which erythrocytes do not maintain their biconcave disc shape but become spherical or have other abnormal shapes and are extremely fragile.269 272 Causes of spherocytosis include defective formation of spectrin tetramers and defective association of spectrin with ankyrin or the band 4.1 protein.265 273 Thus, the principal functions of these proteins in erythrocytes may be to strengthen the membrane and to preserve the characteristic shape of erythrocytes during their 120-day lifetime in the bloodstream. In other cells the spectrins are able to interact with microtubules, which are absent from erythrocytes, and to microtubule-associated proteins of the cytoskeleton (Chapter 7, Section F).270 In nerve terminals a protein similar to erythrocyte protein 4.1 may be involved in transmitter release.274 The cytoskeleton is also actively involved in transmembrane signaling. 

Beilstein, M.A. and Whanger, P.D. 1986. Deposition of dietary organic and inorganic selenium in rat erythrocyte proteins. J. Nutr. 116, 1701-1710. 

Predicting Membrane Protein Topology from Sequence You have cloned the gene for a human erythrocyte protein, which you suspect is a membrane protein. From the nucleotide sequence of the gene, you know the amino acid sequence. From this sequence alone, how would you evaluate the possibility that... 

Fibroblasts were selected because they are readily cultivated and radio-labeled and are available from skin explants of a variety of species. Autoradiograms of radiolabeled cellular proteins are more diverse and easily analyzable for molecular systematics than alternatives such as silver-stained serum or erythrocyte protein patterns. We have achieved nearly 100% success rates at minimal discomfort and risk to human subjects by establishing cultures from 3 mm punch biopsies from the upper buttock. Local lidocaine anesthesia is used. Samples are collected following informed consent and under an approved human research protocol. Other species are sampled by dart gun8 or while sedated. Skin samples can be collected from various body sites without compromising the 2D electrophoresis metric, which does not rely on quantitative differences in protein expression. To comply with the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), tissues collected from wild and captive exotic animals must be obtained under specific permits issued by the U.S. Fish and Wildlife Service. 

Distribution in Blood. Concentrated in the erythrocytes. Protein Binding. In plasma, about 90%. 

Cytochrome exists in a soluble form in erythrocytes and in a membrane bound form in microsomes. A soluble derivative of hepatic cyt bs with 93 amino acids can be isolated by treatment of microsomes with pancreatic lipase and this form has essentially the same amino acid sequence as the erythrocyte protein. Further treatment of the soluble form with trypsin cleaves two residues from the N-terminal and seven from the carboxylate-terminal and leaves the heme core with only 84 residues. Rat liver cyt b has been prepared by expression in Eschericha coli (E.coli). The structure of... 

Moss J, Vaughan M (1978) Isolation of an avian erythrocyte protein possessing ADP-ribosyltransferase activity and capable of activating adenylate cyclase. In Proc. Natl. Acad. Sci. USA 75 3621 -3624. 

As discussed in Chapter 1, at a blood pH of 7.4, the ratio of [HCO3 ] to [H2CO3] is 20 1 and the system s buffering capacity can neutralize a large amount of acid. The system is independently regulated by the kidneys, which control the plasma HCOj level, and by the respiratory rate, which regulates the Pco2- Protein and phosphate buffer systems also operate in plasma and erythrocytes. Proteins are especially important buffers in the intracellular fluid. The hydroxyapatite of bone also acts as a buffer. 

Staufenbiel, M. (1988). Fatty acids covalently bound to erythrocyte proteins undergo a differential turnover in vivo. J Biol Chem, 263 13,615-13,622. 

The muscle protein myoglobin and the erythrocyte protein hemoglobin are both oxygen transport proteins. Describe the structural features that allow these molecules to perform their separate functions. QUESTION 5.1 1... 

Blisnick, T., Vincensini, L., Barale, J. C., Namane, A., and Braun Breton, C. (2005). LANCL1, an erythrocyte protein recruited to the Maurer s clefts during Plasmodium falciparum development. Mol. Biochem. Parasitol. 141,39-47. 

MittI, P.R.E. and G.E. Schulz (1994). The structure of glutathione reductase from Escherichia coli at 1.86A resolution Comparison with the enzyme from human erythrocytes. Protein Sci. 3, 799-809. 

These assessments of Bg nutrition in OCA-users by methods odier than studying tryptophan metabolism do indicate that at least some of the women who excrete abnormal quantities of tryptophan metabolites in urine have a degree of true deficiency in vitamin Bg. However, the possibility that contraceptive steroids may affect binding of B compounds to blood proteins, or to proteins in erythrocyte proteins remains to be explored. 

TABLE 1. A Listing of Serum and Erythrocyte Proteins and Enzymes of Possible Usefulness in the Study of Mutation by... 

The concentration of lead in blood is used as an index of exposure to assess conditions considered to represent a risk to health. Plasma lead concentrations have been shown to be constant at 0.2-0.3 pg/1 over a range of 100-1,500 pg/1 in whole blood showing that lead is bound primarily to erythrocyte protein (chiefly hemoglobin) rather than to stroma [73]. 

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