Glutamic acid polypeptide

Subramanian G, Hjehn RP, Deming TJ, Smith GS, Li Y, Safinya CR (2000) Structure of complexes of cationic lipids and poly(glutamic acid) polypeptides a pinched lamellar phase. J Am Chem Soc 122 26-34... 

Green, M., and Stahmann, M. A. Synthesis and enzymatic hydrolysis of glutamic acid polypeptides. J. Biol. Chem. 197 771—782, 1952. 

Under certain circumstances, many bacteria produce capsules outside their ceU envelopes. Capsules are usually made of polysaccharide however, some Bacillus capsules are composed of D-glutamic acid polypeptide. Certain Gram positive bacteria, most notably strains of Bacillus and Clostridium, produce modified ceUs (endospores) capable of surviving in adverse environments. Spore PG is found between an inner and outer membrane and differs from that in the normal vegetative cell muramic acid is mostly in the lactam form the spore PG has fewer peptide cross-links and the ceU exterior is coated with keratin. The spore also contains large quantities of calcium dipicolinate, a substance involved in microbial heat resistance. 

The data led to tire cycle shown in figure C2.7.8. Here, only tire active site on tire interior enzyme surface (section C2.6) is depicted, consisting of R groups including aspartic acid, glutamic acid and otliers, represented witli tire shortliand Asp, Glu etc tire subscripts represent tlie positions on tlie polypeptide chain. 

FIGURE 19.18 Sickle-shaped red blood cells form when only one amino acid (glutamic acid) in a polypeptide chain is replaced by another amino acid (valine). These cells are less able to take up oxygen than normal cells. 

The digestion of the protein, after heme removal, using Glu-C endoproteinase was also carried out. This enzyme cleaves the polypeptide backbone on the carboxyl terminus of a glutamic acid residue and in this case yielded twelve chromatographic responses. Despite two of these arising from unresolved components, molecular weight information was obtained from 15 polypeptides, one of which was the intact protein, covering the complete sequence, as shown in Table 5.10. 

This polypeptide is structurally identical to ABA-type triblock copolymer with a central hydrophdic elastomeric end-block capped with two hydrophobic plastic end-blocks and exhibits amphiphilic characteristics. The end-blocks of the polymer were chosen in such a way that their LCST would reside at or near room temperature. Thus the polymer exhibits phase separation, which is analogue to conventional TPEs, and offers TPE gels under physiological relevant conditions [104]. Glutamic acid residue is placed periodically in the elastomeric mid-block to increase its affinity towards the aqueous... 

Blout ER, Idelson M (1956) Polypeptides VI. Poly-alpha-glutamic acid preparation and helix-coil conversions. J Am Chem Soc 78 497-498... 

Polypeptides form various secondary structures (a-heUx, 3-sheet, etc.), depending on solution pHs. We have investigated end-anchored poly(L-glutamic acid) andpoly(L-lysine) in various secondary structures [11,29,35,36], using the analytical method for the steric force... 

Sickle hemoglobin A defective form of hemoglobin produced as a result of a single substitution of the amino acid valine for glutamic acid at position 6 of the (1-polypeptide chain. 

One of the amino acids in the beta polypeptide chain of hemoglobin is glutamic acid (Fig. 7.11.1). 

Shimokuri T, Kaneko T, Serizawa T et al (2004) Preparation and thermosensitivity of naturally occurring polypeptide poly(y-glutamic acid) derivatives modified by alkyl groups. Macromol Biosci 4 407-411... 

The most common carrier proteins in use today are keyhole limpet hemocyanin (KLH MW 4.5 X 105 to 1.3 X 107), BSA (MW 67,000), aminoethylated (or cationized) BSA (cBSA), thyroglobulin (MW 660,000), ovalbumin (OVA MW 43,000), and various toxoid proteins, including tetanus toxoid and diphtheria toxoid. Other proteins occasionally used include myoglobin, rabbit serum albumin, immunoglobulin molecules (particularly IgG) from bovine or mouse sera, tuberculin purified protein derivative, and synthetic polypeptides such as poly-L-lysine and poly-L-glutamic acid. 

Aspartic and glutamic acids are themselves negatively charged under physiological conditions. This allows them to chelate certain metal ions, and also to markedly influence the conformation adopted by polypeptide chains in which they are found. 

Considerable amounts of glutamic acid, glycine, and alanine, as well as smaller quantities of aspartic acid, serine, threonine, basic amino acids, leucine, phenylalanine, and cystine have been demonstrated in a total hydrolyzate of the nondiffusible fraction by Boulanger et al. (BIO). Using Deacidite resin, they separated this material into two polypeptide fractions, acid and alkaline, and found that glutamic acid, aspartic acid, leucine, and certain cystine derivatives were the chief constituents of the former, whereas the latter contained considerable amounts of glycine, basic amino acids, and alanine. 

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