発芽ダイズ種子カルボキシペプチダーゼ(第2報) : カルボキシペプチダーゼS_aおよびS_bの安定性, 化学的および動力学的性質

概要

論文の詳細を見る
Carboxypeptidase S_a was composed of 716 amino acid residues, 90 hexose residues (as galactose), and 31 hexosamine residues (as glucosamine) ; these were Trp_<14>, Lys_<42>, His_<15>, Arg_<21>, Asp_<77>, Thr_<42>, Ser_<60>, Glu_<50>, Pro_<34>, Gly_<48>, Ala_<57>, Val_<50>, Met_6,Ile_<56>, Leu_<93>, Tyr_<22>, and Phe_<34>. Carboxypeptidase S_b was composed of 969 amino acid residues but was free from hexose and hexosamines ; these were Trp_<21>, Lys_<62>, His_<19>, Arg_<35>, Asp_<109>, Thr_<49>, Ser_<73>, Glu_<84>, Pro_<49>, Gly_<88>, Ala_<74>, Gys (half)_4,Val_<62>, Met_<15>, Ile_<49>, Leu_<75>, Tyr_<34>, and Phe_<47>. Carboxypeptidase S_a was stable in the pH range from 4.5 to 6.5 and in the temperature range from 0 to 50°, but carboxypeptidase S_b was quickly denatured at pH values below 5.0 or over 6.0. They were completely inhibited by the detergents, sodium dodecyl sulfate and cetyltrimethylammonium bromide, but not by Tween 80 or Triton X-100. The Km and V_<max> values of carboxypeptidase S_a for the hydrolysis of Z-Glu-Phe were 0.16 M and 0.29 μmol/min/・mg, respectively, and those of carboxypeptidase S_b were 0.053 M and 11.36 μmol/min・mg, respectively.
公益社団法人日本薬学会の論文
1976-12-25