PubMed Health⌕ Search

Biomedical subjects

G Wulff

Publications and source records attributed to G Wulff.

At least 19 recordsLinked to original sources
PubMed2001

Stoichiometric noncovalent interaction in molecular imprinting.

In this review article the function of the binding site monomers in the molecular imprinting procedure is discussed. Especially, new developments towards stoichiometric noncovalent interactions are highlighted. In stoichiometric noncovalent interactions template and binding site monomer in an 1:1 molar ratio are nearly completely bound to each other. This is only possible if the association constants are considerably high (Kass > 900 M(-1)). Using this type of interaction in molecular imprinting no excess of binding sites is necessary and binding sites are only located inside the imprinted cavity. Since all cavities can be reloaded these polymers show high capacity (e.g., for preparative application) and are especially suited for the synthesis of catalytically active imprinted polymers. Discussed are binding site interactions based on amidines (and guanidines), multiple hydrogen bonding, charge-transfer interactions, and host-guest inclusion. The systematic investigation of the underlying binding reaction is described in detail. With low-molecular weight model substances the thermodynamics of the association can be conveniently investigated, e.g., by NMR spectroscopy.

Binding Sites↗
PubMed1997

Imprinting techniques in synthetic polymers--new options for chemosensors.

Highly selective molecular recognition in synthetic polymers may be the basis for a new type of chemosensor. For the preparation of such polymers, a molecular imprinting procedure during crosslinking is used to generate, with the aid of template molecules, microcavities of specific shape and with a defined arrangement of functional groups. In this review the role of the polymer matrix and the type of binding site interaction is discussed in more detail. Recent attempts to use these polymers as the basis for chemosensors are highlighted.

Binding Sites↗
PubMed1975

Apolipoproteins in human pregnancy.

Apolipoproteins are important in the structure and metabolism of lipoproteins, and alterations in levels of apoproteins or in their interrelations occur in some forms of hyperlipemia. Pregnancy is regularly accompanied by hyperlipoproteinemia, but while data on lipoprotein lipids is available, the apopipoproteins have not been studied. To characterize the lipemia of pregnancy more completely, we studied some of the apolipoproteins in plasmas of pregnancy women. Thirty-eight normal fasting women were studied between the 18th and 39th weeks of gestation and again 23 plus or minus 17 weeks after delivery. Eight additional women were sampled every 4-6 wk during the second and third trimesters of gestation. Plasma and lipoprotein lipids were assayed by standard procedures and Apolipoprotein B (ApoB) was measured by radioimmunoassay. The interrelations of Apolipoprotein A (ApoA) in high-density lipoprotein (HDL) and of Apolipoprotein C (ApoC) in very-low-density lipoprotein (VLDL) were assessed by disc gel electrophoresis in four women during the last trimester of gestation and again 6-8 mo post partum and in four nongravid controls. Gestational triglycerides (TG) and cholesterol (Chol) were elevated in 95% of the pregnant women. TG in lipoproteins rose progressively during gestation, with VLDL-TG rising the most. Low-density lipoprotein (LDL) and HDL became enriched by TG relative to other components. Total-and VLDL-ApoB increased, while LDL-ApoB remained unchanged, resulting in a change in the density distribution of ApoB. (VLDL-ApoB X 100/total ApoB rose from 3.6% to 6.7%, P less than 0.02.) The accumulation of TG-rich LDL and the increases of VLDL-ApoB may be the result of changes in the rates of secretion or intravascular catabolism of VLDL. Which process is altered remains to be determined. The relative amounts of ApoC-II and ApoC-III in VLDL and the ApoA-I/ApoA-II ratios in HDL were unchanged in pregnancy. These results differ from those seen following high-carbohydrate diets.

Adult↗