title: The roles of AMY1 copies and protein expression in human salivary α-amylase activity.
abstract: Salivary α-amylase (sAA) activity has been extensively investigated in nutrition and psychology. But few studies were performed to assess the role played by sAA gene (AMY1) copies and protein expression in basal and stimulus-induced sAA activity. The sAA activity, amount and AMY1 copy number were determined from 184 saliva samples pre- and post-citric acid stimulation. Our findings showed that citric acid could induce significant increase in sAA activity, total sAA amount, and glycosylated sAA amount, among which the glycosylated sAA amount had the largest response. The correlation analysis showed that AMY1 copy number, total sAA amount and AMY1 copy number×total sAA amount had significantly positive and successively increasing correlations with sAA activity in unstimulated and stimulated saliva, respectively, and furthermore, we observed higher correlations in unstimulated saliva when compared with the corresponding correlations in stimulated saliva. We also observed significant correlations between glycosylated sAA amount and sAA activity in unstimulated and stimulated saliva, respectively. Interestingly, the correlations were higher in stimulated saliva than in unstimulated saliva, and the correlations between glycosylated sAA amount and sAA activity were higher than that of between total sAA amount and sAA activity in stimulated saliva. Moreover, total sAA amount ratio and glycosylated sAA amount ratio showed significantly positive correlation with sAA activity ratio. AMY1 copy number had no correlation with sAA activity ratio. These findings suggested that AMY1 copy number and sAA amount played crucial roles in sAA activity; however, the roles were attenuated after stimulation due to fortified release of glycosylated sAA.
authors.affiliation: School of Basic Courses, Guangdong Pharmaceutical University, China. Electronic address: yzm3102001@gmail.com.
authors.forename: Ze-Min
authors.initials: ZM
authors.lastname: Yang
authors.affiliation: School of Basic Courses, Guangdong Pharmaceutical University, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Lin
authors.affiliation: Pi-Wei Institute, Guangzhou University of Chinese Medicine, China.
authors.forename: Long-Hui
authors.initials: LH
authors.lastname: Chen
authors.affiliation: Pediatrics of Traditional Chinese Medicine, Haizhu Maternal and Child Health Hospital, China.
authors.forename: Min
authors.initials: M
authors.lastname: Zhang
authors.affiliation: Pi-Wei Institute, Guangzhou University of Chinese Medicine, China.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Chen
authors.affiliation: Clinical Laboratory, The First Affiliated Hospital of Guangdong Pharmaceutical University, China.
authors.forename: Xiao-Rong
authors.initials: XR
authors.lastname: Yang
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D019343:Citric Acid / Q000008:administration & dosage; D005260:Female; D018628:Gene Dosage; D006031:Glycosylation; D006801:Humans; D008297:Male; D010812:Physical Stimulation; D012463:Saliva / Q000201:enzymology*; D055291:Salivary alpha-Amylases / Q000235:genetics* / Q000378:metabolism*; D055815:Young Adult
chemical_list: D019343:Citric Acid; C524788:AMY1A protein, human; D055291:Salivary alpha-Amylases
keywords: AMY1 copy number; Activity; Amount; Citric acid stimulation; Glycosylation; Salivary α-amylase