|
[ÇóÖú]
µ×ÎïºÍø´ß»¯·´Ó¦·´Ó¦ÖÐKmÖµºÍKDÖµµÄÏà¹Ø¹Øϵ
´ó¼ÒºÃ£¡ÎÒÔÚÑо¿µ×ÎïºÍøµÄ´ß»¯·´Ó¦Çé¿ö¡£ÎÒÓÃMSTÖ±½Ó²âÁ˵×ÎïÓëøµÄKDÖµ£¬Ò²×öø»îʵÑé²âÁËKmÖµ¡£ÎªÉ¶Éó¸åÈË»áÌá³öKDºÍKmµ¥Î»Ïà²îÖ®´óµÄÎÊÌâÄØ£¿¡°the Kd values were much lower than the Km values measured in the enzyme reactions. Although Kd is not Km, do the authors have an explanation of the large differences ? It is noteworthy that the Kd values determined were in the nanomolar range. The authors are referred to the paper by Yin et al., which determined the Kd for DHT binding to AKR1C2 using transient kinetic approaches and a value of 8 uM was obtained (Biochemistry 2006, 45: 13054).¡±
ƽºâ½âÀë³£ÊýKD=Kd/Ka£¬KDµ¥Î»ÊÇM£¨mol/L£©£»KD=[A][B]/[AB]£¬KD¿ÉÒÔ±íʾ³ö´¦ÓÚƽºâ״̬ʱABµÄ½âÀë³Ì¶È£¬KDÔ½´ó˵Ã÷½âÀëÔ½¶à£¬´ú±íABÖ®¼äÇ׺ÍÁ¦Ô½Èõ£¬KDԽС˵Ã÷½âÀëÔ½ÉÙ£¬´ú±íAB¼äÇ׺ÍÁ¦Ô½Ç¿£»
KmµÄº¬ÒåÊÇø´Ù·´Ó¦´ï×î´óËٶȣ¨Vm£©Ò»°ëʱµÄµ×Îï(S)µÄŨ¶È¡££¬¼´µ±V=Vm/2ʱ£¬¡¾S¡¿=Km,µ¥Î»Îªmol/l¡£KmÊÇø¼«ÎªÖØÒªµÄ¶¯Á¦Ñ§²ÎÊý£¬ÆäÎïÀíº¬ÒåÊÇÖ¸ES¸´ºÏÎïµÄÏûʧËٶȳ£Êý£¨k-1+k2£©ÓëÐγÉËٶȳ£Êý£¨k1£©Ö®±È¡£
³ýÁËËüÃǶ¼±íʾµ×ÎïºÍøµÄÇ׺ÍÁ¦£¨KD±íʾÔÚÎÈ̬Çé¿öϵÄÇ׺ÍÁ¦¡¢Km±íʾÔÚ¶¯Ì¬Çé¿öϵÄÇ׺ÍÁ¦£©Í⣬ËüÃÇÓÐÆäËü¿ÉÒÔ¶ÔÓ¦µÄ¹ØϵÂð£¿
²»Öª¸ÃÈçºÎ»Ø´ðÕâ¸öÎÊÌâ |
|