Peptide surfactants

Drugs, alkaloids, mycotoxins, amino acids, flavinoids, heterocyclic compounds, lipids, steroids, organic acids, terpenes, vitamins. Proteins, peptides, surfactants. 

While the aforementioned technologies focus either on bulk or on solid-phase assembly, a more recent innovation in peptide self-assembly has targeted the soft or fluid-fluid interface. Designer peptides of 7 amino acid "heptad repeats" can be reversibly triggered to fold into an a-helix conformation to organize both hydrophilic and hydrophobic faces, thus inducing surfactant-like structure. These peptide surfactants, however, interact with each other in the interfacial plane, through reversible metal-ion coordination... 

Enkephalin-related peptides [Surfactant], [organic modifier], T, ionic strength tm, R between peptide pairs Four-factor central composite design, RSM, PLS N, tm window, retention factor (36)... 

Amphotropic behavior can be found for a large number of different chemical structures. Additional information is given in other chapters of this Handbook. Typical classes of amphotropic materials are for instance classical soaps (see lyotropics), transition metal soaps (see metallomesogens), viologens, quartemary amines and other ionic surfactants (see lyotropics), block copolymers (see polymer liquid crystals), cellulose derivatives (see cellulose liquid crystals) and partially fluorinated paraffines, diols, peptide surfactants, lecithins, lipids, alkylated sugars and inositols, naturally occurring glycosides and silanols, which are discussed in this chapter. 

Koutsopoulos S, Kaiser L, Eriksson HM, Zhang S (2012) Designer peptide surfactants stabilize diverse iimctimial membrane proteins. Chem Soc Rev 41 1721—1728... 

Peptide surfactants are derived from the condensation of dipeptides or tripeptides and hydrophobic chains such as fatty acids. Most in the literature have been synthesized chemically, although some have been produced biosyntheti-cally. A number of useful reports on peptide surfactants have appeared in the... 

Of the PBS, amino acid surfactants have been the subject of many studies, primarily on their applications as pharmaceuticals, biomedicals, cosmetics, household cleaners, and antimicrobial agents. On the other hand, except for few fragmentary reports, experimental work on peptide surfactants is relatively scanty. Both amino acid surfactants and peptide surfactants are interesting biocompatible compounds that contain amino acid or dipeptide as the hydrophilic part and a long hydrocarbon chain as the hydrophobic part. The hydrocarbon chain can be introduced through acyl, ester, amide, or alkyl linkage. 

The subsequent chapters will discuss the following areas in greater detail structure-function of proteins, with specific reference to their surface property/interfacial behavior, amino acid surfactants, both chemically and enzymatically synthesized peptide surfactants and potential applications and the market assessment of PBS. 

Previous chapters have amply demonstrated that several amino acid surfactants and peptide surfactants have good antimicrobial activities. Understandably, several of the antimicrobial surfactants are still at the experimental stage, but it is important to note that many commercial PBS have been widely used as efficient and safe antimicrobial agents. The biological activity of the PBS antimicrobial activity can range from being specifically bacteriocidal or fungicidal. 

A group of cyclic peptides and peptide surfactants have been examined as potential catalysts for the hydrolysis of esters. Catalysis, inhibition and no activity was observed. ... 

Measurement of correlation times in H2O, dodecane, C2H5OH and sodium dodecyl sulfate solution. ) Measurement of rotational correlation times in starch solution at several temperatures. Measurement of rotational correlation times. ) Measurement of effect of temperature on line broadening. EPR measurement of interaction with peptide surfactant. ) Measurements in several liquid crystal mesophases. ) ESE measurements in sodium dodecyl sulfate micelles. ) EPR measurements made in presence in solution of surfactants. ESE measurements in micellar solutions isomeric radicals also measured. Measurements in sodium dodecyl sulfate micelles and other micellar solutions. ... 

Measurement of interaction with peptide surfactant. °) Measurement of rotational correlation times. 

Peptide surfactants or detergents stabilize membrane proteins, although membrane proteins make up approximately one-third of total cellular proteins and carry out some of the most important functions in cells, only several dozen membrane protein structures have been elucidated. This is in striking contrast to about 33 000 non-membrane protein structures that have been solved [50,51]. 

Fig. 3 Peptide surfactants of A6D and V6D. These simple self-assembling peptide surfac-tant/detergents can be used to solubUize, stabilize and crystallize membrane proteins...

Two key technologies were employed to preserve the functionahty of these photosynthetic complexes outside of their native environment. First, we added two peptide surfactants, one cationic A6K (AAAAAAK), and the other anionic V6D (VVVVVVD) into the photosynthetic complex fraction to... 

Figure 9.4 presents the biosurfactant yield and concentration produced with various waste carbon sources using different Bacillus species. In general, these studies show lower yields and surfactant concentrations than those presented in Figure 9.3. In the case of these Bacillus species, they tend to produce lipo-peptide surfactants, but in some cases they can also produce glycolipids [25]. Similar to the observations in Figure 9.3, sources rich in soluble carbohydrates, such as whey, cassava wastewater, simulated potato waste and molasses, produce poor yields (less than 10% in Figure 9.4) towards the production...

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