嗜铬颗粒蛋白A研究进展

Progresses on Study of Chromogranin A

嗜铬颗粒蛋白A(Chromogranin A,CGA)属于独特的酸性可溶性蛋白质家族,遍布于动物内分泌系统、神经系统和免疫系统,与其他激素和多肽共贮存、共分泌.在CGA上有许多碱性氨基酸对,成为潜在的激素原转化酶切割位点.很多切割产物已经被鉴定,其中有些具有生物学功能.近年的研究表明,在多种病理、生理状态下,CGA及其衍生片段在组织中含量升高,发挥抑制性生理功能或作为疾病诊断指标.嗜铬颗粒蛋白A的N端衍生片段在机体防御系统中的抗菌功能、在心血管系统中的抗血管收缩功能已被阐明,使其作为临床候选药物具有巨大潜力;CGA完整片段在内分泌肿瘤和神经内分泌肿瘤中含量升高,可作为内分泌肿瘤和神经内分泌肿瘤诊断指标,但其在肿瘤发生过程中的作用还未见报道.

Chromogranin A（CGA）belongs to the granin family of uniquely acidic soluble proteins which exhibit widespread distribution in endocrine,nervous and immune system of animals,co-stored and co-secreted with other hormones and peptides.Numerous pairs of basic amino acids indicate potential sites for cleavage by the prohormone convertases.Numerous cleavage products have been identified,some of them with biological activities.It was recently found that CGA levels were enhanced in tissues in many pathological and physical conditions,and CGA and its derived peptides act inhibitory physiological functions or as diagnostic indicators for some diseases.It has been clarified that the N-terminal derived peptides have antimicrobial activities in immune system and vasoinhibitory activity in cardiovascular system,indicate their clinical candidates potency.The level of the whole CGA protein improve in endocrine and neuroendocrine tumors make it be useful in diagnose of endocrine and neuroendocrine tumors,but its function in tumor formation process is not described.