Two japonica rice varieties, Wuyujing 3 and 97-7, were used to study the changes in contents of soluble protein, free amino acids and endopeptidase activity during photosynthetic declination. The content of soluble pr...Two japonica rice varieties, Wuyujing 3 and 97-7, were used to study the changes in contents of soluble protein, free amino acids and endopeptidase activity during photosynthetic declination. The content of soluble protein in flag leaf of cv. Wuyujing 3 was higher than that of cv. 97-7, but decreased rapidly in Wuyujing 3. Free amino acids in flag leaf and the thirteenth leaf of Wuyujing 3 started to increase 10 days before the turning point of photosynthetic declination (TPPD), while it occurred just 1-2 days before TPPD in the flag leaf and the thirteenth leaf of 97-7. During reversible phase of photosynthetic declination, endopeptidase activity remained at a low level and increased slightly only in the later part of this phase. Then it rose up rapidly at irreversible decline phase and reached a very high level. For Wuyujing 3, the change in endopeptidase activity in the thirteenth leaf was parallel to that in flag leaf. However, for 97-7, the rapid increase of endopeptidase activity in the thirteenth leaf started later than that of flag leaf. The results implied that the rate of protein breakdown and conversion to transportable nitrogen in leaves of 97-7 was slower than that in leaves of Wuyujing 3 during photosynthetic declination and it led to relatively lower seed setting rate and fully filling grains rate in 97-7. This may be one of the important reasons why 97-7 could not bring the high yield potentiality into play and the findings may be taken into consideration while breeding for high potential varieties in future.展开更多
The defect of TPP Ⅰ causes a disease, late infantile neuronal ceroid lipofuscinosis（LINCL, CLN2）. To investigate the bio-activity of tripeptidyl peptidase Ⅰ （TPP Ⅰ ） from rat kidneys, the effects of digestion o...The defect of TPP Ⅰ causes a disease, late infantile neuronal ceroid lipofuscinosis（LINCL, CLN2）. To investigate the bio-activity of tripeptidyl peptidase Ⅰ （TPP Ⅰ ） from rat kidneys, the effects of digestion of angiotensin Ⅱ （Ang Ⅱ ） and a synthetic endo-type substrate（ Gly^1-Lys-Pro^5-lie-Pro^5-Phe-Phe-Arg-Leu-Lys^10） via TPP I were ana- lyzed by HPLC and TOF-MS. The data suggest that the degradation rate of Ang I1 can reach 18. 2% by the rat TPP I and DRV（Asp-Arg-Val） can be released from N-termini of Ang Ⅱ within 16 h. In addition, the synthetic endotype substrate is cleaved at the same position between Phe6 and Phe^7. Accordingly, TPP Ⅰ shows two kinds of peptidase activities. One is a tripeptidyl peptidase activity and the other is a pepstatin insensitive carboxyl endopeptidase activity. Tripeptidyl peptidase activity and pepstatin insensitive carboxyl endopeptidase activity seem to be dual phases of one enzyme, TPP Ⅰ.展开更多
文摘Two japonica rice varieties, Wuyujing 3 and 97-7, were used to study the changes in contents of soluble protein, free amino acids and endopeptidase activity during photosynthetic declination. The content of soluble protein in flag leaf of cv. Wuyujing 3 was higher than that of cv. 97-7, but decreased rapidly in Wuyujing 3. Free amino acids in flag leaf and the thirteenth leaf of Wuyujing 3 started to increase 10 days before the turning point of photosynthetic declination (TPPD), while it occurred just 1-2 days before TPPD in the flag leaf and the thirteenth leaf of 97-7. During reversible phase of photosynthetic declination, endopeptidase activity remained at a low level and increased slightly only in the later part of this phase. Then it rose up rapidly at irreversible decline phase and reached a very high level. For Wuyujing 3, the change in endopeptidase activity in the thirteenth leaf was parallel to that in flag leaf. However, for 97-7, the rapid increase of endopeptidase activity in the thirteenth leaf started later than that of flag leaf. The results implied that the rate of protein breakdown and conversion to transportable nitrogen in leaves of 97-7 was slower than that in leaves of Wuyujing 3 during photosynthetic declination and it led to relatively lower seed setting rate and fully filling grains rate in 97-7. This may be one of the important reasons why 97-7 could not bring the high yield potentiality into play and the findings may be taken into consideration while breeding for high potential varieties in future.
文摘The defect of TPP Ⅰ causes a disease, late infantile neuronal ceroid lipofuscinosis（LINCL, CLN2）. To investigate the bio-activity of tripeptidyl peptidase Ⅰ （TPP Ⅰ ） from rat kidneys, the effects of digestion of angiotensin Ⅱ （Ang Ⅱ ） and a synthetic endo-type substrate（ Gly^1-Lys-Pro^5-lie-Pro^5-Phe-Phe-Arg-Leu-Lys^10） via TPP I were ana- lyzed by HPLC and TOF-MS. The data suggest that the degradation rate of Ang I1 can reach 18. 2% by the rat TPP I and DRV（Asp-Arg-Val） can be released from N-termini of Ang Ⅱ within 16 h. In addition, the synthetic endotype substrate is cleaved at the same position between Phe6 and Phe^7. Accordingly, TPP Ⅰ shows two kinds of peptidase activities. One is a tripeptidyl peptidase activity and the other is a pepstatin insensitive carboxyl endopeptidase activity. Tripeptidyl peptidase activity and pepstatin insensitive carboxyl endopeptidase activity seem to be dual phases of one enzyme, TPP Ⅰ.
