Identification Of Calmodulin Binding Proteins In The Process Of Mouse Sperm Capacitation

Calmodulin involves in sperm capacitation.Calmodulin has no enzymatic activity, it is able to adjust and control various physiological activities in living organisms through the interaction with calmodulin binding proteins (CaMBPs). Sperm-specific lactate dehydrogenase C4 (LDH-C4) is a key enzyme of sperm energy metabolism, it is specifically found in the testis tissues and sperms of mammals and birds, and provide energy for sperm motility and capacitation.Objective:1.To extract CaMBPs from spermatozoa in the process of mouse sperm capacitation and identify CaMBPs by MS.2.To study the effect of LDH-C4 on mouse sperm capacitation.Methods:1.After sperm underwent capacitation in vitro, CaMBPs were resolved with SDS-PAGE, then LTQ mass spectrometry was used to identify the CaMBPs.2.In the process of mouse sperm capacitation in vitro, the activity of LDH-C4 was inhibited by sodium oxamite, and the ratio of pattern B sperm was detected by CTC.Results:(1)After mouse sperm capacitation, the rate of acrosome reaction induced by A23187 increased obviously. It showed that sperm capacitated successfully. (2) The map of sperm protein silver staining and coomassie staining were obtained respectively, and the PMF of seven proteins were obtained by MS analysis:lactate dehydrogenase, succinate coenzyme A ligase, dense fiber 2 on the periphery of sperm tail, malate dehydrogenase, pyruvate dehydrogenase El,L-lactate dehydrogenase and pyruvate dehydrogenase a2.(3)After mouse sperm capacitation, the activity of LDH-C4 increased obviously. (4) The activity of LDH-C4 was inhibited and the ratio of pattern B sperm decreased by sodium oxamate.Conclusions:1.Seven CaMBPs were identified in the process of mouse sperm capacitation.2.LDH-C4 involved in sperm capacitation.