title: Characterisation of a thermostable pepstatin-insensitive acid proteinase from a Bacillus sp.

authors: Prescott, Mark

subjects: acid proteinase

abstract: An acid proteinase, Wai 21a, produced by a thermophilic Bacillus species (strain Wai 21a) has been purified to homogeneity by cation-exchange chromatography, phenyl-Sepharose chromatography and anion-exchange chromatography. A pI of 3.8 was determined by isoelectric focussing. The protein contained some associated carbohydrate (20 mol hexose equiv/mol proteinase). Optimal proteolytic activity was observed at pH 3.0 (at 60°C). The Leu¹⁵-Tyr¹⁶ bond was the major site of hydrolysis for the oxidized B chain of insulin. Enzyme activity was not affected by inhibitors of the cysteine, metallo or serine class of proteinases. The aspartate proteinase inhibitor, pepstatin, did not inhibit enzyme activity. Inhibition of enzyme activity by 1,2-epoxy-3-(p-nitrophenoxy)-propane indicated the presence of at least one carboxyl group essential to the catalytic mechanism of the enzyme. Proteinase activity was inhibited by diazoacetyl-  -norleucine methyl ester in a slow and non-specific manner atypical of pepstatin-sensitive aspartate proteinases. Wai 21a proteinase may be classified as member of the pepstatin-insensitive group of aspartate proteinases. The thermal stability at pH 3.0 and 60°C increased 2.1-fold (t1/2, 4.5–9.7 hr) in the presence of 5 mM Ca⁺⁺. An increase in both pH (3.0–4.5) and Ca⁺⁺ concentration (0–30 mM) resulted in a 15-fold increase (t1/2, 15–230 min) in thermal stability at 75°C. The amino acid composition of Wai 21a proteinase was found to be similar to other pepstatin-insensitive proteinases from bacterial sources and in particular similar to the thermostable enzyme, kumamolysin.

text: Characterisation of a thermostable pepstatin-insensitive acid proteinase from a Bacillus sp. An acid proteinase, Wai 21a, produced by a thermophilic Bacillus species (strain Wai 21a) has been purified to homogeneity by cation-exchange chromatography, phenyl-Sepharose chromatography and anion-exchange chromatography. A pI of 3.8 was determined by isoelectric focussing. The protein contained some associated carbohydrate (20 mol hexose equiv/mol proteinase). Optimal proteolytic activity was observed at pH 3.0 (at 60°C). The Leu¹⁵-Tyr¹⁶ bond was the major site of hydrolysis for the oxidized B chain of insulin. Enzyme activity was not affected by inhibitors of the cysteine, metallo or serine class of proteinases. The aspartate proteinase inhibitor, pepstatin, did not inhibit enzyme activity. Inhibition of enzyme activity by 1,2-epoxy-3-(p-nitrophenoxy)-propane indicated the presence of at least one carboxyl group essential to the catalytic mechanism of the enzyme. Proteinase activity was inhibited by diazoacetyl-  -norleucine methyl ester in a slow and non-specific manner atypical of pepstatin-sensitive aspartate proteinases. Wai 21a proteinase may be classified as member of the pepstatin-insensitive group of aspartate proteinases. The thermal stability at pH 3.0 and 60°C increased 2.1-fold (t1/2, 4.5–9.7 hr) in the presence of 5 mM Ca⁺⁺. An increase in both pH (3.0–4.5) and Ca⁺⁺ concentration (0–30 mM) resulted in a 15-fold increase (t1/2, 15–230 min) in thermal stability at 75°C. The amino acid composition of Wai 21a proteinase was found to be similar to other pepstatin-insensitive proteinases from bacterial sources and in particular similar to the thermostable enzyme, kumamolysin.

year: 1995

title: Mineral extraction from New Zealand's geothermal brines: Where to next?

authors: Climo, M.

subjects: New Zealand

abstract: New Zealand’s geothermal brines offer potential for the extraction of various metals and minerals, given both the fluid compositions and volumes discharged. The realisation of commercial value from the extracted constituents could create new industries, support economic development, and potentially provide additional revenue streams for geothermal energy generation and related industries.
A 2013-2015 New Zealand Government-funded research programme (“From Waste to Wealth”) sought to identify potential processing technologies and, in particular, to provide a greater understanding of the barriers and success factors likely to influence the implementation of such technologies.
This paper summarises the research to date and makes recommendations for New Zealand’s future research and investment in this area.

text: Mineral extraction from New Zealand's geothermal brines: Where to next? New Zealand’s geothermal brines offer potential for the extraction of various metals and minerals, given both the fluid compositions and volumes discharged. The realisation of commercial value from the extracted constituents could create new industries, support economic development, and potentially provide additional revenue streams for geothermal energy generation and related industries.
A 2013-2015 New Zealand Government-funded research programme (“From Waste to Wealth”) sought to identify potential processing technologies and, in particular, to provide a greater understanding of the barriers and success factors likely to influence the implementation of such technologies.
This paper summarises the research to date and makes recommendations for New Zealand’s future research and investment in this area.

year: 2015

title: Investigating commentary on the fifth labour-led government’s third way approach

authors: Piercy, Gemma Louise

abstract: After the 1999 election of a Labour-led coalition government in Aotearoa New Zealand, a raft of policy reforms adopted characteristics of the ‘Third Way’ ideology promoted by Anthony Giddens. We argue, however, that Third Way characteristics were not implemented in Aotearoa New Zealand without attracting criticism. This article reviews academic analysis and wider commentary on the Third Way in Aotearoa New Zealand, much of which particularly focused on social policy reforms made by the Labour-led coalition government (1999-2008). We have used this literature to identify the varied ways in which the Third Way was defined and the extent to which Third Way ideology was considered to have influenced policy and practice the Aotearoa New Zealand context. Our semi-systematic literature review shows that many commentators argued that New Zealand did indeed implement a policy platform consistent with Third Way ideological characteristics but these were also adapted to the unique context of Aotearoa New Zealand. We explore in detail two key examples of adaptation di scussed in the literature: the Labour-led government’s early focus on reducing inequalities between Māori and non-Māori and on renewing civil society through subsidiarity and a partnership approach.

text: Investigating commentary on the fifth labour-led government’s third way approach After the 1999 election of a Labour-led coalition government in Aotearoa New Zealand, a raft of policy reforms adopted characteristics of the ‘Third Way’ ideology promoted by Anthony Giddens. We argue, however, that Third Way characteristics were not implemented in Aotearoa New Zealand without attracting criticism. This article reviews academic analysis and wider commentary on the Third Way in Aotearoa New Zealand, much of which particularly focused on social policy reforms made by the Labour-led coalition government (1999-2008). We have used this literature to identify the varied ways in which the Third Way was defined and the extent to which Third Way ideology was considered to have influenced policy and practice the Aotearoa New Zealand context. Our semi-systematic literature review shows that many commentators argued that New Zealand did indeed implement a policy platform consistent with Third Way ideological characteristics but these were also adapted to the unique context of Aotearoa New Zealand. We explore in detail two key examples of adaptation di scussed in the literature: the Labour-led government’s early focus on reducing inequalities between Māori and non-Māori and on renewing civil society through subsidiarity and a partnership approach.

year: 2017