8.A.106.  The Caltrin/Peptide YY (Caltrin/PYY) Family  

Caltrin (calcium transport inhibitor) is a family of small and basic proteins of the mammalian seminal plasma which bind to sperm cells during ejaculation and inhibit the extracellular Ca2+ uptake, preventing the premature acrosomal exocytosis and hyperactivation when sperm cells ascend through the female reproductive tract. The binding of caltrin proteins to specific areas of the sperm surface suggests the existence of caltrin receptors, or precise protein-phospholipid arrangements in the sperm membrane, distributed in the regions where Ca2+ influx may take place (Grasso and Coronel 2017). 

Ghrelin and peptide YY (PYY) are brain-gut peptides that have a variety of physiological functions and are involved in energy regulation (Li et al. 2011). Abnormalities in the expression and secretion of ghrelin and PYY are known to occur in lifestyle-related diseases including obesity, and the improvement of these abnormalities has become an important challenge. Exercise influences ghrelin and PYY concentrations by increasing PYY secretion although ghrelin levels vary with the study subject, timing of exercise, and duration of exercise (Li et al. 2011).  Metformin, the cornerstone of the pharmacological therapy for type 2 diabetes mellitus (T2DM), belongs to the biguanide class of drugs and improves hepatic insulin resistance possibly by enhancing glucagon like peptide-1 (GLP-1) and peptide YY (PYY) secretion (Tavares Bello et al. 2018). GLP-1- and peptide-YY (PYY)-secreting L cells potentially have antidiabetic and antiobesity effects (Christiansen et al. 2018).


 

References:

Christiansen, C.B., M.B.N. Gabe, B. Svendsen, L.O. Dragsted, M.M. Rosenkilde, and J.J. Holst. (2018). The impact of short-chain fatty acids on GLP-1 and PYY secretion from the isolated perfused rat colon. Am. J. Physiol. Gastrointest Liver Physiol 315: G53-G65.

Fry, B.G., K. Winter, J.A. Norman, K. Roelants, R.J. Nabuurs, M.J. van Osch, W.M. Teeuwisse, L. van der Weerd, J.E. McNaughtan, H.F. Kwok, H. Scheib, L. Greisman, E. Kochva, L.J. Miller, F. Gao, J. Karas, D. Scanlon, F. Lin, S. Kuruppu, C. Shaw, L. Wong, and W.C. Hodgson. (2010). Functional and structural diversification of the Anguimorpha lizard venom system. Mol. Cell Proteomics 9: 2369-2390.

Grasso, E.J. and C.E. Coronel. (2017). Structure and Function of Caltrin (Calcium Transport Inhibitor) Proteins. Biochem Insights 10: 1178626417745822.

Krauhs, E., K.D. Preuss, and K.H. Scheit. (1990). Functional properties of peptides derived from seminalplasmin: binding to monospecific anti-seminalplasmin immunoglobulins G and calmodulin. Biol Chem Hoppe Seyler 371: 111-116.

Lafferty, R.A., P.R. Flatt, and N. Irwin. (2018). Emerging therapeutic potential for peptide YY for obesity-diabetes. Peptides 100: 269-274.

Li, J.B., A. Asakawa, Y. Li, K. Cheng, and A. Inui. (2011). Effects of exercise on the levels of peptide YY and ghrelin. Exp Clin Endocrinol Diabetes 119: 163-166.

Tavares Bello, C., R. Castro Fonseca, F. Sousa Santos, J. Sequeira Duarte, J. Azinheira, and C. Vasconcelos. (2018). Renal function markers and metformin eligibility. Minerva Endocrinol 43: 246-252.

Examples:

TC#NameOrganismal TypeExample
8.A.106.1.1

Caltrin of 80 aas and 1 N-terminal TMS.  Caltrin (calcium transport inhibitor) is a family of small, basic proteins of the mammalian seminal plasma which bind to sperm cells during ejaculation and inhibit the extracellular Ca2+ uptake, preventing the premature acrosomal exocytosis and hyperactivation when sperm cells ascend through the female reproductive tract (Grasso and Coronel 2017). It binds calmodullin but not calcium.  It also inhibits the growth of microorganisms, possibly by acting as an antibiotic, permeabilizing the bacterial membrane (Krauhs et al. 1990).

Caltrin of Bos taurus (Bovine)

 
8.A.106.1.2

caltrin isoform X2 of 117 aas and 1 TMS

Caltrin X2 of Ovis aries musimon

 
Examples:

TC#NameOrganismal TypeExample
8.A.106.2.1

Peptide YYA precursor of 97 aas and 1 N-terminal TMS.  Peptide YY (PYY) influences appetite suppression and body weight, probably through interaction of PYY with hypothalamic Y2 receptors (Lafferty et al. 2018).

PYY of Danio rerio

 
8.A.106.2.2

Goannatyrotoxin-Vere1 of 99 aas and 1 N-terminal TMS (Fry et al. 2010). 

Goannatyrotoxin-Vere1 from the venom of Varanus eremius (the Pygmy desert monitor lizard)