title: The structure and function of a bovine salivary protein - BSP30b

authors: Zhang, Heng

subjects: TULIP

abstract: The Bovine Salivary Protein 30b (BSP30b) is a member of the palate, lung, and nasal  epithelium  clone  (PLUNC)  family  which  includes  human bactericidal/permeability-increasing protein (BPI) and lipopolysaccaride binding protein (LBP). BSP30b is predominantly found in bovine saliva but its function is not understood. Although PLUNC family members are proposed to be lipid binding proteins, in most cases their lipid ligands are also unknown.
Here, the X-ray crystal structure of BSP30b is solved at 2 Å resolution using a double methionine mutant and Se-Met MAD phasing. Each molecule adopts a slightly curved cylindrical structure with a hydrophobic channel formed by an α/β wrap, which is highly conserved in the PLUNC family. The structure of BSP30b complexed with oleic acid is also presented where the ligand is accommodated within the hydrophobic channel. The electron density for oleic acid suggests that the ligand is only partially occupied in the binding site implying that oleic acid might not be the preferred ligand of BSP30b.
Nonetheless, GFP-tagged BSP30b binds to the surface of olive oil droplets, as observed by fluorescent microscopy. Bacteria extracted directly from rumen samples indicate that the GFP_BSP30b fusion protein binds to a small number of selected bacterial strains in vivo. These results suggest that BSP30b could have a specific range of lipid ligands and may play important roles via its interaction with select rumen bacteria.

text: The structure and function of a bovine salivary protein - BSP30b The Bovine Salivary Protein 30b (BSP30b) is a member of the palate, lung, and nasal  epithelium  clone  (PLUNC)  family  which  includes  human bactericidal/permeability-increasing protein (BPI) and lipopolysaccaride binding protein (LBP). BSP30b is predominantly found in bovine saliva but its function is not understood. Although PLUNC family members are proposed to be lipid binding proteins, in most cases their lipid ligands are also unknown.
Here, the X-ray crystal structure of BSP30b is solved at 2 Å resolution using a double methionine mutant and Se-Met MAD phasing. Each molecule adopts a slightly curved cylindrical structure with a hydrophobic channel formed by an α/β wrap, which is highly conserved in the PLUNC family. The structure of BSP30b complexed with oleic acid is also presented where the ligand is accommodated within the hydrophobic channel. The electron density for oleic acid suggests that the ligand is only partially occupied in the binding site implying that oleic acid might not be the preferred ligand of BSP30b.
Nonetheless, GFP-tagged BSP30b binds to the surface of olive oil droplets, as observed by fluorescent microscopy. Bacteria extracted directly from rumen samples indicate that the GFP_BSP30b fusion protein binds to a small number of selected bacterial strains in vivo. These results suggest that BSP30b could have a specific range of lipid ligands and may play important roles via its interaction with select rumen bacteria.

year: 2019

title: High-resolution radiocarbon chronologies and synchronization of records

authors: Hajdas, Irka

abstract: It is now accepted that the precise dating of certain periods is complicated by extreme variability of atmospheric ¹⁴C content shown at times in the ¹⁴C calibration curve. This complication arises from variations in atmospheric ¹⁴C content and is known as wiggles in the calibration curve. Radiocarbon age ‘plateaus’, are caused by a decrease in the atmospheric ¹⁴C concentration and appear as a slowing down of the ¹⁴C clock such as occurred during the Younger Dryas (YD) chronozone. In effect, similar ¹⁴C ages apply across a range of up to 500 calendar years. The opposite is observed when atmospheric ¹⁴C levels increase so that the ¹⁴C clock appears to speed up. In such cases, which include the beginning of the YD and Pre-Boreal intervals, the true age of a sample, taking dating errors into account, may spread across a comparatively wide ¹⁴C age range

text: High-resolution radiocarbon chronologies and synchronization of records It is now accepted that the precise dating of certain periods is complicated by extreme variability of atmospheric ¹⁴C content shown at times in the ¹⁴C calibration curve. This complication arises from variations in atmospheric ¹⁴C content and is known as wiggles in the calibration curve. Radiocarbon age ‘plateaus’, are caused by a decrease in the atmospheric ¹⁴C concentration and appear as a slowing down of the ¹⁴C clock such as occurred during the Younger Dryas (YD) chronozone. In effect, similar ¹⁴C ages apply across a range of up to 500 calendar years. The opposite is observed when atmospheric ¹⁴C levels increase so that the ¹⁴C clock appears to speed up. In such cases, which include the beginning of the YD and Pre-Boreal intervals, the true age of a sample, taking dating errors into account, may spread across a comparatively wide ¹⁴C age range

year: 2006

title: Wearing moko: Maori facial marking in today’s world

authors: Nikora, Linda Waimarie

subjects: moko

abstract: The early voyagers, missionaries, settlers all reacted to the pukanohi, to the marked faces of the Maori people, during the period of first contact, and the century following it. Their accounts are vivid, judgemental, revealing, telling us as much about them as they do about the people they described.
Curiosity and horror are mixed with a genuine
fascination; where sternly evangelizing words
failed, armed confrontation occurred; and we
now live with the results, te ao hou, a new world. In this world, today, wahine mau kauae, tangata mau moko, pukanohi – wearers – are speaking for themselves, about themselves, and commenting on how others view them. Unanimously, they insist that the decision to take the marking is about continuity, affirmation, identity and commitment. It is also about wearing those ancestors, carrying them into the future; as their moko become a companion, a salient being with its own life force, its own integrity and power, beyond the face.

text: Wearing moko: Maori facial marking in today’s world The early voyagers, missionaries, settlers all reacted to the pukanohi, to the marked faces of the Maori people, during the period of first contact, and the century following it. Their accounts are vivid, judgemental, revealing, telling us as much about them as they do about the people they described.
Curiosity and horror are mixed with a genuine
fascination; where sternly evangelizing words
failed, armed confrontation occurred; and we
now live with the results, te ao hou, a new world. In this world, today, wahine mau kauae, tangata mau moko, pukanohi – wearers – are speaking for themselves, about themselves, and commenting on how others view them. Unanimously, they insist that the decision to take the marking is about continuity, affirmation, identity and commitment. It is also about wearing those ancestors, carrying them into the future; as their moko become a companion, a salient being with its own life force, its own integrity and power, beyond the face.

year: 2004-04-04