Amino Acids

, Volume 40, Issue 4, pp 1053–1063 | Cite as

Proline and hydroxyproline metabolism: implications for animal and human nutrition

  • Guoyao WuEmail author
  • Fuller W. Bazer
  • Robert C. Burghardt
  • Gregory A. Johnson
  • Sung Woo Kim
  • Darrell A. Knabe
  • Peng Li
  • Xilong Li
  • Jason R. McKnight
  • M. Carey Satterfield
  • Thomas E. Spencer
Invited Review


Proline plays important roles in protein synthesis and structure, metabolism (particularly the synthesis of arginine, polyamines, and glutamate via pyrroline-5-carboxylate), and nutrition, as well as wound healing, antioxidative reactions, and immune responses. On a per-gram basis, proline plus hydroxyproline are most abundant in collagen and milk proteins, and requirements of proline for whole-body protein synthesis are the greatest among all amino acids. Therefore, physiological needs for proline are particularly high during the life cycle. While most mammals (including humans and pigs) can synthesize proline from arginine and glutamine/glutamate, rates of endogenous synthesis are inadequate for neonates, birds, and fish. Thus, work with young pigs (a widely used animal model for studying infant nutrition) has shown that supplementing 0.0, 0.35, 0.7, 1.05, 1.4, and 2.1% proline to a proline-free chemically defined diet containing 0.48% arginine and 2% glutamate dose dependently improved daily growth rate and feed efficiency while reducing concentrations of urea in plasma. Additionally, maximal growth performance of chickens depended on at least 0.8% proline in the diet. Likewise, dietary supplementation with 0.07, 0.14, and 0.28% hydroxyproline (a metabolite of proline) to a plant protein-based diet enhanced weight gains of salmon. Based on its regulatory roles in cellular biochemistry, proline can be considered as a functional amino acid for mammalian, avian, and aquatic species. Further research is warranted to develop effective strategies of dietary supplementation with proline or hydroxyproline to benefit health, growth, and development of animals and humans.


Proline Nutrition Biochemistry Health Growth 



Amino acid


Intrauterine growth retardation


Mammalian target of rapamycin


National Research Council





This work was supported, in part, by grants from National Institutes of Health (1R21 HD049449), National Research Initiative Competitive Grants (2008-35206-18764, 2008-35203-19120, and 2009-35206-05211) from the USDA Cooperative State Research, Education, Texas AgriLife Research (H-8200), North Carolina Agricultural Experiment Station, and the Thousand-People-Talent program at China Agricultural University. We thank graduate students, postdoctoral fellows, technicians, and many collaborators for their important contributions to the work described in this article.


  1. Aksnes A, Mundheim H, Toppe J et al (2006) The effect of dietary hydroxyproline supplementation on salmon (Salmo salar L.) fed high plant protein diets. Aquaculture 275:242–249CrossRefGoogle Scholar
  2. Austic RE (1976) Nutritional and metabolic interrelationships of arginine, glutamic acid and proline in the chicken. Fed Proc 35:1914–1916PubMedGoogle Scholar
  3. Baker DH (2009) Advances in protein-amino acid nutrition of poultry. Amino Acids 37:29–41PubMedCrossRefGoogle Scholar
  4. Ball RO, Atkinson JL, Bayley HS (1986) Proline as an essential amino acid for the young pig. Br J Nutr 55:659–668PubMedCrossRefGoogle Scholar
  5. Barbul A (2008) Proline precursors to sustain mammalian collagen synthesis. J Nutr 138:2021S–2024SPubMedGoogle Scholar
  6. Bergen WG, Wu G (2009) Intestinal nitrogen recycling and utilization in health and disease. J Nutr 139:821–825PubMedCrossRefGoogle Scholar
  7. Blachier F, Lancha AH Jr, Boutry C et al (2010) Alimentary proteins, amino acids and cholesterolemia. Amino Acids 38:15–22PubMedCrossRefGoogle Scholar
  8. Brandsch M (2006) Transport of l-proline, l-proline-containing peptides and related drugs at mammalian epithelial cell membranes. Amino Acids 31:119–136PubMedCrossRefGoogle Scholar
  9. Chandel NS (2010) Mitochondrial regulation of oxygen sensing. Adv Exp Med Biol 661:339–354PubMedCrossRefGoogle Scholar
  10. Chen LX, Li P, Wang JJ et al (2009) Catabolism of nutritionally essential amino acids in developing porcine enterocytes. Amino Acids 37:143–152PubMedCrossRefGoogle Scholar
  11. Chung TK, Baker DH (1993) A note on the dispensability of proline for weanling pigs. Anim Prod 56:407–408CrossRefGoogle Scholar
  12. Dai ZL, Zhang J, Wu G et al (2010) Utilization of amino acids by bacteria from the pig small intestine. Amino Acids. doi: 10.1007/s00726-010-0556-9
  13. Davis TA, Nguyen HV, Garciaa-Bravo R et al (1994) Amino acid composition of human milk is not unique. J Nutr 124:1126–1132PubMedGoogle Scholar
  14. Dillon EL, Knabe DA, Wu G (1999) Lactate inhibits citrulline and arginine synthesis from proline in pig enterocytes. Am J Physiol Gastrointest Liver Physiol 276:G1079–G1086Google Scholar
  15. Elango R, Ball RO, Pencharz PB (2009) Amino acid requirements in humans: with a special emphasis on the metabolic availability of amino acids. Amino Acids 37:19–27PubMedCrossRefGoogle Scholar
  16. Ferreira AG, Lima DD, Delwing D et al (2010) Proline impairs energy metabolism in cerebral cortex of young rats. Metab Brain Dis 25:161–168PubMedCrossRefGoogle Scholar
  17. Flynn NE, Bird JG, Guthrie AS (2009) Glucocorticoid regulation of amino acid and polyamine metabolism in the small intestine. Amino Acids 37:123–129PubMedCrossRefGoogle Scholar
  18. Fu WJ, Stromberg AJ, Viele K et al (2010) Statistics and bioinformatics in nutritional sciences: analysis of complex data in the era of systems biology. J Nutr Biochem 21:561–572PubMedCrossRefGoogle Scholar
  19. Gorres KL, Raines RT (2010) Prolyl 4-hydroxylase. Crit Rev Biochem Mol Biol 45:106–124PubMedCrossRefGoogle Scholar
  20. Gottlob RO, DeRouchey JM, Tokach MD et al (2006) Amino acid and energy digestibility of protein sources for growing pigs. J Anim Sci 84:1396–1402PubMedGoogle Scholar
  21. Graber G, Baker DH (1971) Ornithine utilization by the chick. Proc Soc Exp Biol Med 138:585–588PubMedGoogle Scholar
  22. Graber G, Allen NK, Scott HM (1970) Proline essentiality and weight gain. Poul Sci 49:692–697Google Scholar
  23. Hansen JA, Knabe DA, Burgoon KG (1993) Amino acid supplementation of low-protein sorghum-soybean meal diets for 20- to 50-kilogram swine. J Anim Sci 71:442–451PubMedGoogle Scholar
  24. Haynes TE, Li P, Li XL et al (2009) l-Glutamine or l-alanyl-l-glutamine prevents oxidant- or endotoxin-induced death of neonatal enterocytes. Amino Acids 37:131–142PubMedCrossRefGoogle Scholar
  25. He QH, Kong XF, Wu GY et al (2009) Metabolomic analysis of the response of growing pigs to dietary l-arginine supplementation. Amino Acids 37:199–208PubMedCrossRefGoogle Scholar
  26. Hu CA, Khalil S, Zhaorigetu S et al (2008) Human ∆1-pyrroline-5-carboxylate synthase: function and regulation. Amino Acids 35:665–672PubMedCrossRefGoogle Scholar
  27. Jobgen W, Fu WJ, Gao H et al (2009) High fat feeding and dietary l-arginine supplementation differentially regulate gene expression in rat white adipose tissue. Amino Acids 37:187–198PubMedCrossRefGoogle Scholar
  28. Kaul S, Sharma SS, Mehta IK (2008) Free radical scavenging potential of l-proline: evidence from in vitro assays. Amino Acids 34:315–320PubMedCrossRefGoogle Scholar
  29. Kim SW, Wu G (2004) Dietary arginine supplementation enhances the growth of milk-fed young pigs. J Nutr 134:625–630PubMedGoogle Scholar
  30. Kim SW, Wu G (2009) Regulatory role for amino acids in mammary gland growth and milk synthesis. Amino Acids 37:89–95PubMedCrossRefGoogle Scholar
  31. Kirchgessner VM, Rader G, Roth-Maier DA (1991) Influence of an oral arginine supplementation on lactation performance of sows. J Anim Physiol Anim Nutr 66:38–44CrossRefGoogle Scholar
  32. Kirchgessner M, Fickler J, Roth FX (1995) Effect of dietary proline supply on N-balance of piglets. 3. Communication on the importance of nonessential amino acids for protein retention. J Anim Physiol Anim Nutr 73:57–65CrossRefGoogle Scholar
  33. Knabe DA, LaRue DC, Gregg EJ et al (1989) Apparent digestibility of nitrogen and amino acids in protein feedstuffs by growing pigs. J Anim Sci 67:441–458PubMedGoogle Scholar
  34. Krane SM (2008) The importance of proline residues in the structure, stability and susceptibility to proteolytic degradation of collagens. Amino Acids 35:703–710PubMedCrossRefGoogle Scholar
  35. Kwon H, Spencer TE, Bazer FW et al (2003a) Developmental changes of amino acids in ovine fetal fluids. Biol Reprod 68:1813–1820PubMedCrossRefGoogle Scholar
  36. Kwon H, Wu G, Bazer FW et al (2003b) Developmental changes in polyamine levels and synthesis in the ovine conceptus. Biol Reprod 69:1626–1634PubMedCrossRefGoogle Scholar
  37. LaRue DC, Knabe DA, Tanskley TD Jr (1985) Commercially processed glandless cottonseed meal for starter, grower and finisher swine. J Anim Sci 60:495–502Google Scholar
  38. Li P, Yin YL, Li DF et al (2007) Amino acids and immune function. Br J Nutr 98:237–252PubMedCrossRefGoogle Scholar
  39. Li P, Mai KS, Trushenski J et al (2009a) New developments in fish amino acid nutrition: towards functional and environmentally oriented aquafeeds. Amino Acids 37:43–53PubMedCrossRefGoogle Scholar
  40. Li XL, Bazer FW, Gao HJ et al (2009b) Amino acids and gaseous signaling. Amino Acids 37:65–78PubMedCrossRefGoogle Scholar
  41. Li P, Kim SW, Li XL et al (2009c) Dietary supplementation with cholesterol and docosahexaenoic acid affects concentrations of amino acids in tissues of young pigs. Amino Acids 37:709–716PubMedCrossRefGoogle Scholar
  42. Li XL, Bazer FW, Johnson GA et al (2010) Dietary supplementation with 0.8% l-arginine between days 0 and 25 of gestation reduces litter size in gilts. J Nutr 140:1111–1116PubMedCrossRefGoogle Scholar
  43. Liao XH, Majithia A, Huang XL et al (2008) Growth control via TOR kinase signaling, an intracellular sensor of amino acids and energy availability, with crosstalk potential to proline metabolism. Amino Acids 35:761–770PubMedCrossRefGoogle Scholar
  44. Lin FD, Knabe DA, Tanksley TD Jr (1987) Apparent digestibility of amino acids, gross energy and starch in corn, sorghum, wheat, barley, oat groats and wheat middlings for growing pigs. J Anim Sci 64:1655–1663PubMedGoogle Scholar
  45. Mateo RD, Wu G, Moon HK et al (2008) Effects of dietary arginine supplementation during gestation and lactation on the performance of lactating primiparous sows and nursing piglets. J Anim Sci 86:827–835PubMedCrossRefGoogle Scholar
  46. Motyl T, Ploszaj T, Wojtasik A et al (1995) Polyamines in cow’s and sow’s milk. Comp Biochem Physiol B 111:427–433PubMedCrossRefGoogle Scholar
  47. Mutch DM, Wahli W, Williamson G (2005) Nutrigenomics and nutrigenetics: the emerging faces of nutrition. FASEB J 19:1602–1616PubMedCrossRefGoogle Scholar
  48. National Research Council (NRC) (1998) Nutrient requirements of swine, 10th edn. National Academy Press, Washington, DCGoogle Scholar
  49. O’Quinn PR, Knabe DA, Wu G (2002) Arginine catabolism in lactating porcine mammary tissue. J Anim Sci 80:467–474PubMedGoogle Scholar
  50. Oka T, Perry JW (1974) Arginase affects lactogenesis through its influence on the biosynthesis of spermidine. Nature 250:660–661PubMedCrossRefGoogle Scholar
  51. Palii SS, Kays CE, Deval C et al (2009) Specificity of amino acid regulated gene expression: analysis of gene subjected to either complete or single amino acid deprivation. Amino Acids 37:79–88PubMedCrossRefGoogle Scholar
  52. Pérez-Arellano I, Carmona-Alvarez F, Martínez AI et al (2010) Pyrroline-5-carboxylate synthase and proline biosynthesis: from osmotolerance to rare metabolic disease. Protein Sci 19:372–382PubMedGoogle Scholar
  53. Phang JM, Donald SP, Pandhare J et al (2008) The metabolism of proline, as a stress substrate, modulates carcinogenic pathways. Amino Acids 35:681–690PubMedCrossRefGoogle Scholar
  54. Phang JM, Liu W, Zabirnyk O (2010) Proline metabolism and microenvironmental stress. Annu Rev Nutr 30:441–463Google Scholar
  55. Pistollato F, Persano L, Rampazzo E et al (2010) l-Proline as a modulator of ectodermal differentiation in ES cells. Am J Physiol Cell Physiol 298:C979–C981PubMedCrossRefGoogle Scholar
  56. Reeds PJ, Burrin DG (2001) Glutamine and the bowel. J Nutr 131:2505S–2508SPubMedGoogle Scholar
  57. Reynolds LP, Caton JS, Redmer DA et al (2006) Evidence for altered placental blood flow and vascularity in compromised pregnancies. J Physiol 572:51–58PubMedGoogle Scholar
  58. Rhoads JM, Wu G (2009) Glutamine, arginine, and leucine signaling in the intestine. Amino Acids 37:111–122CrossRefGoogle Scholar
  59. Satterfield MC, Bazer FW, Spencer TE, Wu G (2010) Sildenafil citrate treatment enhances amino acid availability in the conceptus and fetal growth in an ovine model of intrauterine growth restriction. J Nutr 140:251–258PubMedCrossRefGoogle Scholar
  60. Sjostrom H, Noren O, Josefsson L (1973) Purification and specificity of pig intestinal prolidase. Biochim Biophys Acta 327:457–470PubMedGoogle Scholar
  61. Srivastava D, Zhu W, Johnson WH Jr et al (2010) The structure of the proline utilization a proline dehydrogenase domain inactivated by N-propargylglycine provides insight into conformational changes induced by substrate binding and flavin reduction. Biochemistry 49:560–569PubMedCrossRefGoogle Scholar
  62. Stipanuk MH, Ueki I, Dominy JE et al (2009) Cysteine dioxygenase: a robust system for regulation of cellular cysteine levels. Amino Acids 37:55–63PubMedCrossRefGoogle Scholar
  63. Suryawan A, O’Connor PMJ, Bush JA et al (2009) Differential regulation of protein synthesis by amino acids and insulin in peripheral and visceral tissues of neonatal pigs. Amino Acids 37:97–104PubMedCrossRefGoogle Scholar
  64. Tan BE, Li XG, Kong XF et al (2009a) Dietary l-arginine supplementation enhances the immune status in early-weaned piglets. Amino Acids 37:323–331PubMedCrossRefGoogle Scholar
  65. Tan BE, Yin YL, Liu ZQ et al (2009b) Dietary l-arginine supplementation increases muscle gain and reduces body fat mass in growing-finishing pigs. Amino Acids 37:169–175PubMedCrossRefGoogle Scholar
  66. van Meijl LE, Popeijus HE, Mensink RP (2010) Amino acids stimulate Akt phosphorylation, and reduce IL-8 production and NF-kappaB activity in HepG2 liver cells. Mol Nutr Food Res doi: 10.1002/mnfr.200900438
  67. Verbruggen N, Hermans C (2008) Proline accumulation in plants: a review. Amino Acids 35:753–759PubMedCrossRefGoogle Scholar
  68. Wang W, Qiao S, Li D (2009a) Amino acids and gut function. Amino Acids 37:105–110PubMedCrossRefGoogle Scholar
  69. Wang XQ, Ou DY, Yin JD et al (2009b) Proteomic analysis reveals altered expression of proteins related to glutathione metabolism and apoptosis in the small intestine of zinc oxide-supplemented piglets. Amino Acids 37:209–218PubMedCrossRefGoogle Scholar
  70. Wang J, Ma H, Tong C et al (2010) Overnutrition and maternal obesity in sheep pregnancy alter the JNK-IRS-1 signaling cascades and cardiac function in the fetal heart. FASEB J 24:2066–2076PubMedCrossRefGoogle Scholar
  71. Watford M (2008) Glutamine metabolism and function in relation to proline synthesis and the safety of glutamine and proline supplementation. J Nutr 138:2003S–2007SPubMedGoogle Scholar
  72. Wenger RH, Hoogewijs D (2010) Regulated oxygen sensing by protein hydroxylation in renal erythropoietin-producing cells. Am J Physiol Renal Physiol 298:F1287–F1296PubMedCrossRefGoogle Scholar
  73. Wu G (1993) Determination of proline by reversed-phase high performance liquid chromatography with automated pre-column o-phthaldialdehyde derivatization. J Chromatogr 641:168–175CrossRefGoogle Scholar
  74. Wu G (1997) Synthesis of citrulline and arginine from proline in enterocytes of postnatal pigs. Am J Physiol Gastrointest Liver Physiol 272:G1382–G1390Google Scholar
  75. Wu G (1998) Intestinal mucosal amino acid catabolism. J Nutr 128:1249–1252PubMedGoogle Scholar
  76. Wu G (2009) Amino acids: metabolism, functions, and nutrition. Amino Acids 37:1–17PubMedCrossRefGoogle Scholar
  77. Wu G, Knabe DA (1994) Free and protein-bound amino acids in sow’s colostrum and milk. J Nutr 124:415–424PubMedGoogle Scholar
  78. Wu G, Morris SM Jr (1998) Arginine metabolism: nitric oxide and beyond. Biochem J 336:1–17PubMedGoogle Scholar
  79. Wu G, Self JT (2005) Proteins. In: Pond WG, Bell AW (eds) Encyclopedia of animal science. Marcel Dekker, New York, pp 757–759Google Scholar
  80. Wu G, Borbolla AG, Knabe DA (1994) The uptake of glutamine and release of arginine, citrulline and proline by the small intestine of developing pigs. J Nutr 124:2437–2444PubMedGoogle Scholar
  81. Wu G, Bazer FW, Tuo W (1995a) Developmental changes of free amino acid concentrations in fetal fluids of pigs. J Nutr 125:2859–2868PubMedGoogle Scholar
  82. Wu G, Knabe DA, Yan W et al (1995b) Glutamine and glucose metabolism in enterocytes of the neonatal pig. Am J Physiol Regulatory Integr Comp Physiol 268:R334–R342Google Scholar
  83. Wu G, Meier SA, Knabe DA (1996) Dietary glutamine supplementation prevents jejunal atrophy in weaned pigs. J Nutr 126:2578–2584PubMedGoogle Scholar
  84. Wu G, Ott TL, Knabe DA et al (1999) Amino acid composition of the fetal pig. J Nutr 129:1031–1038PubMedGoogle Scholar
  85. Wu G, Flynn NE, Knabe DA (2000) Enhanced intestinal synthesis of polyamines from proline in cortisol-treated piglets. Am J Physiol Endocrinol Metab 279:E395–E402PubMedGoogle Scholar
  86. Wu G, Bazer FW, Cudd TA et al (2004) Maternal nutrition and fetal development. J Nutr 134:2169–2172PubMedGoogle Scholar
  87. Wu G, Bazer FW, Hu J et al (2005) Polyamine synthesis from proline in the developing porcine placenta. Biol Reprod 72:842–850PubMedCrossRefGoogle Scholar
  88. Wu G, Bazer FW, Wallace JM et al (2006) Intrauterine growth retardation: Implications for the animal sciences. J Anim Sci 84:2316–2337PubMedCrossRefGoogle Scholar
  89. Wu G, Bazer FW, Cudd TA et al (2007a) Pharmacokinetics and safety of arginine supplementation in animals. J Nutr 137:1673S–1680SPubMedGoogle Scholar
  90. Wu G, Bazer FW, Davis TA et al (2007b) Important roles for the arginine family of amino acids in swine nutrition and production. Livest Sci 112:8–22CrossRefGoogle Scholar
  91. Wu G, Bazer FW, Datta S et al (2008) Proline metabolism in the conceptus: Implications for fetal growth and development. Amino Acids 35:691–702PubMedCrossRefGoogle Scholar
  92. Wu G, Bazer FW, Davis TA et al (2009) Arginine metabolism and nutrition in growth, health and disease. Amino Acids 37:153–168PubMedCrossRefGoogle Scholar
  93. Wu G, Bazer FW, Burghardt RC et al (2010a) Impacts of amino acid nutrition on pregnancy outcome in pigs: mechanisms and implications for swine production. J Anim Sci 88:E195–E204PubMedCrossRefGoogle Scholar
  94. Wu G, Bazer FW, Burghardt RC (2010b) Functional amino acids in swine nutrition and production. In: Doppenberg J et al (eds) Dynamics in animal nutrition. Wageningen Academic Publishers, The Netherlands, pp 69–98Google Scholar
  95. Zeng XF, Wang FL, Fan X et al (2008) Dietary arginine supplementation during early pregnancy enhances embryonic survival in rats. J Nutr 138:1421–1425PubMedGoogle Scholar
  96. Zhang Y, Dabrowski K, Hliwa P et al (2006) Indispensable amino acid concentrations decrease in tissues of stomachless fish, common carp in response to free amino acid- or peptide-based diets. Amino Acids 31:165–172PubMedCrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2010

Authors and Affiliations

  • Guoyao Wu
    • 1
    • 5
    Email author
  • Fuller W. Bazer
    • 1
  • Robert C. Burghardt
    • 2
  • Gregory A. Johnson
    • 2
  • Sung Woo Kim
    • 3
  • Darrell A. Knabe
    • 1
  • Peng Li
    • 4
  • Xilong Li
    • 1
  • Jason R. McKnight
    • 1
  • M. Carey Satterfield
    • 1
  • Thomas E. Spencer
    • 1
  1. 1.Department of Animal Science and Faculty of NutritionTexas A&M UniversityCollege StationUSA
  2. 2.Department of Veterinary Integrative BiosciencesTexas A&M UniversityCollege StationUSA
  3. 3.Department of Animal ScienceNorth Carolina State UniversityRaleighUSA
  4. 4.National Renderers AssociationAlexandriaUSA
  5. 5.State Key Laboratory of Animal NutritionChina Agricultural UniversityBeijingChina

Personalised recommendations