Lipid assisted membrane entry in specific phospholipid targeted protein systems

The purpose of this thesis project is to study changes in the physical state of cell membranes during cell entry, including how these changes are connected to the presence of ceramide. The role of enzymatical manipulation of lipids in bacterial internalization is also studied. A novel technique, where a single giant vesicle is chosen under the microscope and an enzyme coupled-particle attached to the micromanipulator pipette towards the vesicle, is used. Thus, the enzymatic reaction on the membrane of the giant vesicle can be followed in real-time. The first aim of this study is to develop a system where the localized sphingomyelinase membrane interaction could be observed on the surface of the giant vesicle and the effects could be monitored with microscopy. Domain formation, which resembles acid sphingomyelinase (ASMase), causes CD95 clustering in the cell membrane due to ceramide production (Grassmé et al., 2001a; Grassmé et al., 2001b) and the formation of small vesicles inside the manipulated giant vesicle is observed. Sphingomyelinase activation has also been found to be an important factor in the bacterial and viral invasion process in nonphagocytic cells (Grassmé et al., 1997; Jan et al., 2000). Accordingly, sphingomyelinase reactions in the cell membrane might also give insight into bacterial or viral cellular entry events. We found sphingomyelinase activity in Chlamydia pneumonia elementarybodies (EBs). Interestingly, the bacterium enters host cells by endocytosis but the internalization mechanism of Chlamydia is unknown. The hypothesis is that sphingomyelin is needed for host cell entry in the infection of C. pneumonia. The second project focuses on this subject. The goal of the third project is to study a role of phosphatidylserine as a target for a membrane binding protein. Phosphatidylserine is chosen because of its importance in fusion processes. This will be another example for the importance of lipids in cell targeting, internalization, and externalization.

Vanhurskautta, oikeutta vai uskollisuutta? : ṣdq -sanue vuoden 1992 Kirkkoraamatun Psalmien kirjassa

Righteousness, justice or faithfulness? The Hebrew Root ṣdq in the Psalter of the Finnish Church Bible of 1992 This study attempts to answer three questions. Firstly, what do the derivates of the root ṣdq mean in the Hebrew Psalter? Secondly, with which equivalents are these Hebrew words translated in the Psalter of the Finnish Church Bible of 1992 and why? And thirdly, how is the translation of the root ṣdq in the Psalter placed in comparison with the translations of the root ṣdq in certain ancient and modern Bible translations? The root ṣdq has a very wide semantic field in Biblical Hebrew. The basic meaning of the root ṣdq is ‘right’ or ‘to be in the right’. The traditional English equivalent of the root ṣdq is righteousness. In many European languages the equivalent of the root ṣdq has some connection with the word ‘right’, but this is not the case in Finnish. The Finnish word vanhurskaus has been present since the first Finnish Bible translation by Mikael Agricola in 1548. However, this word has nothing to do with the Finnish word for ‘right’. The word vanhurskaus has become a very specific religious and theological word in Finnish, and it can be a word that is not obvious or at all understandable even to a native Finnish speaker. In the Psalter of the earlier Finnish Church Bible of 1938 almost every derivate of the root ṣdq (132/139) was translated as vanhurskaus. In the Psalter of the Finnish Church Bible of 1992 less than half of these derivates (67/139) are translated as that. Translators have used 20 different equivalents of the Hebrew derivates of the root ṣdq. But this type of translation also has its own problems. The most disputed is the fact that in it the Bible reader finds no connections between many Bible verses that have obvious connections with each other in the Hebrew Bible. For example, in verse Ps. 118, 15 one finds a Finnish word for ‘saved’ and in verse Ps. 142, 8 one finds another Finnish word for ‘friends’, while in the Hebrew Bible the same word is used in both verses, ṣaddîqīm. My study will prove that it is very challenging to compare or fit together the semantics of these two quite different languages. The theoretical framework for the study consists of biblical semantic theories and Bible translation theories. Keywords: religious language, Bible translations, Book of Psalms.

Silva Fennica Vol. 19, 1985.

Julkaistu Silva Fennica Vol. 19(4) -numeron liitteenä.