Glutamic-acid-rich proteins

The role of the glutamic-acid-rich proteins in rod photoreceptors... 

Y. Sugimoto, K. Yatsunami, M. Tsujimoto, H. G. Khorana, and A. Ichikawa. The aminoacid sequence of a glutamic acid-rich protein from bovine retina as deduced from the cDNA sequence. Proc Nad Acad. Set, USA, 88, 3116-3119, 1991. 

Poetsch, A., Molday, L.L. and Molday, R.S. (2001) The cGMP-gated channel and related glutamic acid-rich proteins interact with peripherin-2 at the rim region of rod photoreceptor disc membranes. J. Biol. 

Heating of foods rich in proteins may lead to formation of crosslinking isopeptide bonds between the S-NH2 group of lysine and the p- and y-carboxyl groups of aspartic and glutamic acid residues or their amides. 

A protein that is rich in glutamic acid and aspartic acid will be rich in what kind of functional groups present as substituents on the alpha-carbon Will it be attracted, in electrophoresis, to the positive or negative side What is this kind of protein polymer called ... 

A short half-life of proteins is often associated with proline, glutamic acid, serine and threonine-rich regions (so-called PEST-rich regions) [Rechsteiner,... 

In egg shells of reptiles, three different types of egg shell protein with a high proline content connected with the presence of cysteine. Another type of reptile egg shell proteins is proline-rich but free of crysteine (first observed in Phelsuma egg shells). A further type of egg shell proteins has first been observed in Tarentola (gekko) egg shells it is practically cysteine-free, but contains high proportions of aspartic acid, glutamic acid, lysine and serine380. ... 

The amelogenins are hydrophobic but are also rich in proline, histidine, and glutamic acid.3/b They account for 90% of the matrix proteins but are replaced by the initially less abundant enamelins1 in fully mineralized teeth.a d Another protein present in developing enamel is ameloblastin, which appears to be unique to amyloblasts.3 As mineralization of the enamel progresses the matrix is lost and 98% of the enamel is hydroxylapatite.3... 

Human saliva is supersaturated with basic calcium phosphate, to allow recalcification and protection of the dental enamel. Precipitation in the saliva is prevented by certain calcium binding proteins, which include statherin268 (a 5380 molecular weight tyrosine-rich protein that also contains many proline and glutamic acid residues), and a group of proline-rich proteins.269... 

Most shells or exoskeletons are made of crystalline minerals, but amorphous calcium carbonate (ACC) is also present. These biological ACC contain significant amounts of Mg, P and rich glutamic acid proteins. ... 

Table XI also compares the amino acid analyses of Merino 64 s wool with that of cuticle obtained by subjecting the wool to ultrasonic irradiation in 98 % formic acid (Bradbury and Chapman, 1964). The cuticle contained less arginine, aspartic acid, glutamic acid, leucine, and phenylalanine than whole wool, but more cystine, proline, serine, and valine. Cys-teic acid is probably formed during the ultrasonic treatment. These analyses cannot be accounted for quantitatively on the basis of a simple combination of low-sulfur and high-sulfur protein fractions, but the data suggest that the cuticle would not contain as much material in the a-helical conformation as the original fiber. The values obtained by Bradbury (1960) in an earlier examination of cuticle-rich material obtained by a mechanical descaling technique are in reasonable agreement with the values in Table XI.

Additional evidence for a bacterial contribution to HMW DOM proteins comes from molecular-level analyses of dissolved amino acids. Hydrolysis of HMW DON releases 11-29% of the nitrogen as amino acids (McCarthy et al., 1996). Specific amino acids include common protein amino acids, as well as /3-alanine and y-aminobutyric acid which are nonprotein amino acid degradation products. The distribution of amino acids is similar to that of fresh plankton cells, suspended particulate matter, and total dissolved amino acids. However, stereochemical analyses show HMW DOM amino acids to be elevated in the D-enantiomer, with d/l ratios for alanine, aspartic acid, glutamic acids, and serine ranging from 0.1 to 0.5 (McCarthy et al., 1998). Racemization of phytoplankton-derived L-amino acids is too slow at ocean temperatures to yield such high D/L ratios, but bacteria can synthesize D-amino acids, and it is likely that the D-amino acids in HMW DOM result from bacterial bioploymers rich in these particular amino acids. The high dA ratios of some amino acids and the abundance of amide nitrogen in HMW DOM N-NMR spectra led McCarthy et al. (1998) to... 

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