The influence of various lipids on the activity of bovine milk galactosyltransferase

1980 ◽  
Vol 58 (10) ◽  
pp. 809-814 ◽  
Author(s):  
M. M. Mitranic ◽  
M. A. Moscarello
Keyword(s):  
Phase Transition ◽  
Fatty Acid ◽  
Phosphatidic Acid ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Physical State ◽  
Bovine Milk ◽  
Head Group ◽  
Head Groups ◽  
Fatty Acid Compositions

Purified bovine milk galactosyltransferase was combined with liposomes of different lipid composition. The activity was markedly affected by the nature of the lipid used. Thus phosphatidylcholine, phosphatidylethanolamine, and phosphatidylglycerol stimulated the activity, while phosphatidic acid and phosphatidylserine inhibited the activity of the transferase. Phosphatidylcholine, phosphatidylglycerol, and phosphatidic acid had identical fatty acid compositions, yet phosphatidylcholine and phosphatidylglycerol stimulated the activity while phosphatidic acid inhibited the activity. The effect on the enzyme was probably related to the nature of the head group since the inhibition by phosphatidic acid could be converted to stimulation by methylating the phosphatidic acid. The properties of several of the head groups is discussed. The physical state of the lipid was shown to affect the activity markedly. When the enzyme was combined with dimyristylphosphatidylcholine the activity was markedly stimulated when the lipid was in the liquid-crystalline state i.e., above the phase transition.

Cone-shaped lipids increase the susceptibility of phospholipids in bilayers to the action of phospholipases

1985 ◽  
Vol 63 (4) ◽  
pp. 263-267 ◽  
Author(s):  
James Thomas Buckley
Keyword(s):  
Fatty Acid ◽  
Snake Venom ◽  
Bilayer Lipid ◽  
Polar Head ◽  
Pancreatic Phospholipase ◽  
Head Groups ◽  
Nonbilayer Lipids ◽  
Monogalactosyl Diglyceride ◽  
Fatty Acid Compositions ◽  
Stimulation Of

Addition of cardiolipin or diacylglycerol to dispersions of phosphatidylcholine greatly increased hydrolysis by snake venom or pancreatic phospholipase A2, as well as by a microbial phospholipase. Monogalactosyl diglyceride which, like cardiolipin and diacylglycerol, will form nonbilayer hexagonal II structures also caused an increase in the breakdown of phosphatidylcholine. Addition of digalactosyl diglyceride, a bilayer lipid from the same source, had a much smaller effect on the three phospholipases, indicating that stimulation by the nonbilayer lipids was not due to their fatty acid compositions. Stimulation of the microbial phospholipase by cardiolipin did not require the presence of calcium, leading to the conclusion that the formation of nonbilayer structures was not necessary. The results suggest that cone-shaped lipids increase the accessibility of lipids in bilayers to phospholipases by decreasing the packing of the polar head groups.

scholarly journals Head-group Dependent Domain Morphologies in Langmuir Monolayers

1970 ◽  
Vol 46 (1) ◽  
pp. 47-52
Author(s):  
MM Hossain ◽  
T Kato
Keyword(s):  
Phase Transition ◽  
Langmuir Monolayers ◽  
Brewster Angle ◽  
Head Group ◽  
Critical Surface ◽  
Brewster Angle Microscopy ◽  
Head Groups ◽  
Air Water Interface ◽  
Surface Morphologies ◽  
Internal Texture

The effect of head groups on the thermodynamic properties and morphological features of the domains formed in the Langmuir monolayers at 10 oC has been investigated by a film balance and a Brewster angle microscopy (BAM). 2-hydroxyethyl myristate (2-HEM) and n-tetradecanoyl N-ethanolamide (NHEA-14), having the same chain length but different head groups have been taken as amphiphiles. Both the amphiphiles represent a first-order LE-LC phase transition at 10 oC at the air-water interface. The critical surface pressure necessary for this phase transition is 6.0 mN/m for 2-HEM and 1.0 mN/m for NHEA-14. The surface morphologies of the domains are entirely different. The domains of 2-HEM are circular having internal texture, while those of NHEA-14 are dendritic having directional characteristics. The presence of interfacial hydrogen bonding in the latter amphiphile should be responsible for the formation of such characteristic domains in the case of latter amphiphile. Key words: Langmuir monolayers; Phase transition; Brewster angle microscopy; 2-hydroxyethyl myristate; n-tetradecanoyl Nethanolamide. DOI: http://dx.doi.org/10.3329/bjsir.v46i1.8104 Bangladesh J. Sci. Ind. Res. 46(1), 47-52, 2011

Effect of phase transitions on the interaction of peptides and proteins with phospholipids

1984 ◽  
Vol 62 (11) ◽  
pp. 1167-1173 ◽  
Author(s):  
Richard M. Epand ◽  
Witold K. Surewicz
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Transition Temperature ◽  
Protein Interactions ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Protein Protein Interactions ◽  
Lipid Interactions ◽  
Liquid Crystalline State ◽  
Protein Incorporation

This review is not a comprehensive study of the broad area of lipid–protein interactions, but rather concentrates on the question of the effect of phase transitions on the interaction of peptides and proteins with phospholipids. Before considering the relative ability of peptides and proteins to incorporate into phospholipid bilayers in the gel or the liquid crystalline state, we briefly review the variety of effects of proteins on lipid phase transitions. It is essential to be cognizant of these effects when discussing how-phase transitions affect protein incorporation. The effect of proteins on lipid order and motion above and below the phase transition is discussed and the current state of knowledge on this topic is briefly reviewed. In discussing the thermodynamics of lipid–protein association and the effect of phase transitions one must deal with systems at equilibrium, a state often difficult to achieve with high molecular weight aggregates. It is demonstrated that there are a variety of effects of phase transitions on protein incorporation. Some proteins incorporate more readily into liquid crystalline state lipid; others incorporate only in a narrow temperature region around the phase transition temperature, while still others interact with lipid over a broad range of temperatures while exhibiting some preference for interacting with gel state lipid. The molecular basis for preferential interaction with gel state lipid is suggested to be the ability of proteins to self-associate, probably at defect sites, below the phase transition temperature and thereby increase protein–protein interactions while maintaining protein–lipid and lipid–lipid interactions. In liquid crystalline state lipid, the protein would be more dispersed, the system would become less stable as a result of decreased protein–protein interactions, and the dispersed protein would also lessen lipid–lipid interactions. The ability of several peptides and proteins to intercalate more readily into gel rather than liquid crystalline state lipid is a more common phenomenon than is generally appreciated.

Comparison of Fatty Acid Compositions and Tocopherols in Perilla germplasm of South Korea

2017 ◽  
Author(s):  
JS Sung ◽  
YJ Jeong ◽  
DJ Kim ◽  
YY Lee ◽  
YA Jeon ◽  
...  
Keyword(s):  
Fatty Acid ◽  
South Korea ◽  
Fatty Acid Compositions

Self-Assembly Optical Components

2003 ◽  
Vol 771 ◽  
Author(s):  
Pavel I. Lazarev ◽  
Michael V. Paukshto ◽  
Elena N. Sidorenko
Keyword(s):  
Optical Properties ◽  
Self Assembly ◽  
Crystalline State ◽  
Liquid Crystalline ◽  
Film Deposition ◽  
X Ray Diffraction ◽  
Optical Components ◽  
Crystal Film ◽  
Solid Film ◽  
Thin Crystal

AbstractWe report a new method of Thin Crystal Film deposition. In the present paper we describe the method of crystallization, structure, and optical properties of Bisbenzimidazo[2,1-a:1',2',b']anthra[2,1,9-def:6,5,10-d'e'f']-diisoquinoline-6,9-dion (mixture with cis-isomer) (abbreviated DBI PTCA) sulfonation product. The Thin Crystal Film has a thickness of 200-1000 nm, with anisotropic optical properties such as refraction and absorption indices. X-ray diffraction data evidences a lyotropic liquid crystalline state in liquid phase and crystalline state in solid film. Anisotropic optical properties of the film make it useful in optical devices, e.g. liquid crystal displays.

Serum Fatty Acid Compositions and Lipid Concentrations and Their Correlations.

1996 ◽  
Vol 20 (2) ◽  
pp. 149-159 ◽  
Author(s):  
Toshichika TAKITA ◽  
Kahoru NAKAMURA ◽  
Mitsuru KIMIRA ◽  
Norihiro YAMADA ◽  
Yoshie KOBAYASHI ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Serum Fatty Acid ◽  
Fatty Acid Compositions
Sign in / Sign up

Export Citation Format

Share Document